SYSTEMATIC REVIEW article

Front. Psychiatry, 25 November 2020

Sec. Behavioral and Psychiatric Genetics

Volume 11 - 2020 | https://doi.org/10.3389/fpsyt.2020.550225

Genetic Determinants of Gating Functions: Do We Get Closer to Understanding Schizophrenia Etiopathogenesis?

  • 1. Department of Behavioural Neuroscience, Institute of Normal and Pathological Physiology, Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovakia

  • 2. Social, Cognitive and Affective Neuroscience Unit, Department of Cognition, Emotion, and Methods in Psychology, Faculty of Psychology, University of Vienna, Vienna, Austria

Abstract

Deficits in the gating of sensory stimuli, i.e., the ability to suppress the processing of irrelevant sensory input, are considered to play an important role in the pathogenesis of several neuropsychiatric disorders, in particular schizophrenia. Gating is disrupted both in schizophrenia patients and their unaffected relatives, suggesting that gating deficit may represent a biomarker associated with a genetic liability to the disorder. To assess the strength of the evidence for the etiopathogenetic links between genetic variation, gating efficiency, and schizophrenia, we carried out a systematic review of human genetic association studies of sensory gating (suppression of the P50 component of the auditory event-related brain potential) and sensorimotor gating (prepulse inhibition of the acoustic startle response). Sixty-three full-text articles met the eligibility criteria for inclusion in the review. In total, 117 genetic variants were reported to be associated with gating functions: 33 variants for sensory gating, 80 variants for sensorimotor gating, and four variants for both sensory and sensorimotor gating. However, only five of these associations (four for prepulse inhibition—CHRNA3 rs1317286, COMT rs4680, HTR2A rs6311, and TCF4 rs9960767, and one for P50 suppression—CHRNA7 rs67158670) were consistently replicated in independent samples. Although these variants and genes were all implicated in schizophrenia in research studies, only two polymorphisms (HTR2A rs6311 and TCF4 rs9960767) were also reported to be associated with schizophrenia at a meta-analytic or genome-wide level of evidence. Thus, although gating is widely considered as an important endophenotype of schizophrenia, these findings demonstrate that evidence for a common genetic etiology of impaired gating functions and schizophrenia is yet unsatisfactory, warranting further studies in this field.

Introduction

Sensory and sensorimotor gating are conceptualized as basic cognitive processes that regulate the processing of sensory input by the brain. It has been suggested that gating represents a filtering mechanism, preventing distraction and sensory overload, or a protective mechanism, securing uninterrupted processing of stimuli (14). Importantly, it has been further postulated that disrupted gating may contribute to information processing deficits, cognitive fragmentation, and thought disorder, the hallmark feature of schizophrenia psychosis (58).

Sensory gating is routinely examined by measuring the electroencephalographic event-related potentials (ERPs) during a paired-pulse paradigm (7). The paradigm comprises trials with two identical auditory stimuli of the same intensity, a conditioning stimulus (S1) and a testing stimulus (S2), that are presented successively with an interstimulus interval of 500 ms (9, 10). Auditory stimuli elicit an ERP, which is characterized by a positive peak ~40–90 ms after stimulus onset, known as P50 wave. It has been suggested that response to S1 triggers an inhibitory mechanism that results in a reduced amplitude of the P50 wave after the presentation of S2. The diminution of the P50 wave to S2 relative to that elicited by S1, called P50 suppression or P50 gating, is the operational definition of sensory gating (7, 10, 11). Other well-established, but less commonly assessed, measures of sensory gating include the suppression of the N100 and P200 ERP waves (12, 13). The most widely used measure of sensorimotor gating, on the other hand, is prepulse inhibition (PPI) of the acoustic startle reflex. During the PPI paradigm, the presentation of a sudden and intense auditory startling stimulus (pulse) is preceded (usually 30–120 ms) by a weaker non-startling stimulus (prepulse). This leads to a reduction in the startle reflex also known as PPI. In humans, PPI is commonly quantified by measuring the eye-blink component of the startle reflex using electromyography of the periocular muscles (1416).

Both PPI and P50 gating are robustly reduced in schizophrenia spectrum disorders [e.g., (1720)], but also several other psychiatric conditions, in particular, bipolar disorder and obsessive–compulsive disorder [e.g., (2128), for review see e.g., (29, 30)]. Deficits in PPI and P50 gating were reported not only in psychiatric patients but also in their unaffected first-degree relatives [(19, 3133), for a recent review of PPI studies see ref. (34)]. Several studies have demonstrated a significant heritability of these measures, ranging 29–58% for PPI and 10–68% for P50 gating (31, 3542). Given these attributes, including a high test–retest reliability, PPI and P50 suppression deficits are considered as important endophenotypes of neuropsychiatric disorders (20, 37), i.e., intermediate phenotypes (or markers) that are associated with disorders but are simpler in terms of the genetic and neurobiological architecture (4345). Endophenotypes represent an important approach to deal with the complexity and polygenic nature of mental disorders such as schizophrenia. It is supposed that studying the genetic architecture of endophenotypes and their relationship with biological processes impaired in neuropsychiatric disorders may contribute to a better understanding of the underlying pathophysiology [e.g., (46)]. The genetic basis of gating in humans has been intensively studied over the last decades, and it has become apparent that a significant genetic component is involved in both PPI and P50 suppression. Despite an extensive and rapidly growing body of literature on the relationship between genotype and gating in humans, the underlying genetic architecture of these endophenotypes remains elusive due to fragmentary evidence and lack of verification. Recently, Quednow et al. (47) carried out a systematic review (and a meta-analysis) of human association studies of PPI (sensorimotor gating). However, a similar assessment of sensory gating studies is lacking, as is an integrative review of genetic determinants of both sensory and sensorimotor gating functions. The aim of this work was thus to evaluate current knowledge regarding the etiopathogenetic links between genetic variation, gating efficiency, and schizophrenia. For this purpose, we carried out a systematic review of published genetic association studies assessing the relationship between genetic variation and the efficiency of sensory and sensorimotor gating in humans. Furthermore, we critically assessed the reliability of these findings by examining the quality of the studies, the number of replications, and the relative number of positive and negative results. Finally, we evaluated the evidence for genetic mechanisms shared between gating and schizophrenia.

Materials and Methods

Study Design

The review process followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (48). The Covidence online software (Covidence systematic review software, Veritas Health Innovation, Melbourne, Australia; available at www.covidence.org) was used to facilitate the process of screening, paper selection, and data extraction.

Search Strategy

To identify eligible studies, we performed a systematic, comprehensive search of the published literature using Pubmed and Scopus until October 2019. The electronic databases were searched using the combination of Boolean operators and the following key words: sensorimotor gating, sensory gating, prepulse inhibition, P50, startle, polymorphism, gene and human, among others (for exact search phrases utilized, see Supplementary Data 1). Also, a secondary search of relevant articles was performed by screening the references of included full-text papers.

Inclusion Criteria and Study Selection

To be included in the review a study had to meet the following inclusion criteria: (1) study design of a candidate gene association study (CGAS), genome-wide association study (GWAS), or included these studies as a part of more complex study design (e.g., pharmacogenetic study), (2) study enrolled human subjects (healthy participants or psychiatric patients), (3) study outcomes included sensorimotor gating as indexed by PPI or sensory gating indices such as P50, N100, or P200 suppression, and (4) the report was written in English. Only original research papers were included; other article types, such as reviews, meta-analyses, case reports, editorials, and commentaries, were excluded.

The search results were imported to the Covidence, and after removing duplicates, titles and abstracts of identified studies were independently screened by the first and the second author (RR and DB). At this stage, only irrelevant studies that obviously did not meet the inclusion criteria were excluded from the review. Next, for the remaining potentially eligible papers, the same two authors independently assessed full texts to select only those articles that meet all of the abovementioned inclusion criteria. Any disagreement between the two reviewers was discussed and resolved by consensus. If needed, the third author (IR) was involved to reach a decision.

Data Extraction

The following information was extracted from the selected studies: name of the first author, affiliation of the first author, year of publication, country, study design, sample characteristics (sample size, mean age, sex ratio, race/ethnicity, inclusion/exclusion criteria and population—healthy vs. psychiatric patients), parameters of the auditory stimulation (duration and intensity of acoustic stimuli, background sound intensity, and sound frequency), electrode placement, statistical test used, description of assessed polymorphisms (polymorphism type, reference number/label, chromosomal position, closest gene, reference and minor allele frequency, functional consequence, and association with disorders), and study outcomes of interest (genotype effects on PPI and sensory gating across all samples including p-value, effect size, direction of the effect, mean values, and standard deviations). The data extraction was carried out by DB and RR, working independently and in duplicate, using the Covidence data extraction tool. All data extraction forms from both reviewers were inspected for potential errors and compiled by RR.

Quality Assessment

The quality of genetic studies (Q-Genie) 11-item tool was used to evaluate the quality of all included studies. We opted for this tool since it was specifically developed and validated to facilitate the assessment of the global quality of genetic association studies, and it proved to be valid and reliable for both expert and non-expert raters (49). The quality assessment was conducted by DB and RR, working independently and in duplicate. The final quality score for each study was calculated by averaging the respective scores from the two reviewers. Following the Q-Genie scoring system, scores below 33 indicate poor-quality studies, scores between 33 and 40 indicate studies of moderate quality, and scores above 40 indicate good-quality studies. The degree of interobserver agreement was tested using the Cohen's kappa coefficient (κ), with values categorized as poor (≤0.20), fair (0.21–0.40), moderate (0.41–0.60), substantial (0.61–0.80), and almost perfect agreement (>0.80) (50). The Cohen's kappa coefficient was computed by using the FREQ procedure in SAS Studio software (SAS University Edition, release 3.8, SAS Institute, Cary, NC, USA).

Results

Identification of Relevant Studies

The systematic search yielded 1,820 potentially relevant references. After removing 369 duplicates and 1,326 irrelevant articles identified by screening abstracts, the full texts of the remaining 125 papers were assessed for eligibility. Of them, excluded were 39 studies that did not meet the inclusion criteria and 16 duplicates not captured by Covidence, leaving 70 papers. Based on the Q-Genie scoring system, 41 out of the 70 relevant studies (58.6%) were rated high quality, 22 (31.4%) moderate, and 7 (10.0%) poor. A weighted kappa value of 0.55, 95% CI (0.50–0.60) indicates a moderate agreement between the two raters (DB and RR). Poor-quality studies were excluded from the systematic review due to concerns about the validity of results, leaving 63 eligible papers. No additional papers were identified by screening the references of the included articles. The process of study selection is depicted in the PRISMA flow diagram below (Figure 1).

Figure 1

Basic Description of the Included Studies

The final selection included 53 CGAS, 3 GWAS, and seven pharmacogenetic studies (25, 52113). These studies investigated in total 63 independent sample groups: 36 samples of healthy individuals, 20 patient samples (16 with schizophrenia), and seven samples involving both patients and healthy individuals. Sensorimotor gating (PPI) was assessed in 41 studies, sensory gating (P50 or N100 suppression, for simplicity thereafter referred to as P50 gating) in 18 studies, and four studies assessed both measures. A short summary of the basic characteristics of the studies is provided in Table 1; details for each study included in this review are provided in Supplementary Table 1.

Table 1

No. of samplesSample sizeGating measure
Study designNo. of studiesTotalHealthyPatients (SZ)MixedMeanSDRangePPIP50Both
CGAS53532820 (16)515324423–1,82134154
GWAS34202719385306–1,212210
Pharmacogenetic76600574123–114520
Total63633620 (16)741184

Overview of the basic characteristics of the studies included in the review (25, 52113).

CGAS, candidate gene association study; GWAS, genome-wide association study; SZ, patients with schizophrenia; PPI, prepulse inhibition of the acoustic startle reflex; P50, suppression of wave P50 or N100 of the auditory evoked potential.

Identification and Description of Genetic Polymorphisms

Data extraction from the eligible studies resulted in the identification of 201 polymorphisms located within or close to 77 genes. Association with PPI was tested for 125 polymorphisms. Among them, 84 variants, within or close to 37 genes, were reported as significantly (p < 0.05) associated with PPI in at least one sample. Association with P50 gating was investigated for 109 polymorphisms, of which 37, located within or close to 13 genes, were significantly associated with this measure in at least one sample. Association with both PPI and P50 gating was investigated in 54 variants and a significant association with both measures was reported for four polymorphisms (COMT rs4680, rs165599, ANKK1 rs1800497, and TCF4 rs9960767). A vast majority of the variants were single nucleotide polymorphisms (SNPs, Table 2; for a detailed summary see Supplementary Tables 2–5).

Table 2

Reported associationsPositive associationsc
Gating measureNo. of investigated variantsaSig.bNonsig.SNPNonSNPGenes
PPI12584 (3)100651937
P5010937 (9)8530713

Overview of the reported associations with gating measures.

a

Includes only variants investigated in candidate gene association studies and pharmacogenetic studies.

b

Associations reported as significant (p < 0.05), number in parentheses: no. of significant associations reported in genome-wide association studies.

c

No. of variants/genes positively associated with gating function in at least one study. PPI, prepulse inhibition of the acoustic startle reflex; P50, suppression of wave P50 or N100 of the auditory evoked potential; SNP, single nucleotide polymorphisms; non-SNP, includes copy number variants, combined genotype, haplotypes, genetic interaction, indels, short tandem repeats.

To provide insight into the involved biological mechanism, we conducted an enrichment analysis using the Gene Ontology Resource (114116). The associated variants were annotated by dbSNP and clustered based on the overrepresentation of the corresponding genes in the Gene Ontology classification section Biological Processes. The results of this analysis are provided in Table 3. Associations were considered as consistent (reliable) if a significant association with PPI or P50 gating was reported in at least two independent samples, and the number of reported significant associations was higher than the number of null findings. For both PPI and P50 gating, the reported positive associations included several genes involved in neurodevelopmental processes and/or cellular signaling (in particular glutamatergic, dopaminergic, serotoninergic, and cholinergic neurotransmission). However, most of the polymorphisms for which positive associations were reported were explored in only one published study (PPI: 64.3%, P50: 81.1%). Applying our criterion of reliability, only four associations with PPI (CHRNA3 rs1317286, COMT rs4680, HTR2A rs6311, and TCF4 rs9960767) and one with P50 gating (CHRNA7 rs67158670) can be considered as consistent.

Table 3

Gene ontology category (Section biological processes)Genes with positive associationsReliable associationsa
Nervous system developmentPPI: AUTS2, AVPR1A, CTNNA2, ERBB4, KCNQ2, NCAM1, NGF, NOS1, NRG1, OXTR, RELN, TCF4, TSPAN2
P50: DISC1, ERBB4, FLRT2, TCF4
PPI: TCF4 rs9960767
Synaptic transmission, glutamatergicPPI: GRID2, GRIK3, GRIN2A, GRIN3A, GRIN3B
P50: GRID2, GRIK4
Synaptic transmission, cholinergicPPI: CHRNA3, CHRNA4, CHRNA7
P50: CHRNA7c, CHRFAM7A
PPI: CHRNA3 rs1317286 P50: CHRFAM7A rs67158670
GPCR signaling pathway, coupled to cyclic nucleotide second messengerPPI: DRD2, DRD3, HTR1Ac, HTR2A
P50: GRM3
PPI: HTR2A rs6311
Regulation of calcium ion transportPPI: CAMK2A, FMR1, NOS1AP
P50: CACNAC1
Neurotransmitter reuptakePPI: SLC1A2, SLC6A3
P50: SLC6A3
Dopamine metabolic processPPI: COMT, DAO, DBH
P50: COMT
PPI: COMT rs4680
Serotonin metabolic processPPI: TPH2b
Proline metabolic processPPI: PRODH
UnclassifiedPPI: ANKK1, KPNA4
P50: ANKK1

Summary of genes and genetic variants associated with gating functions.

a

Criteria of reliability: significant association was reported in at least two independent samples and the number of reported significant associations was higher than number of reported null results.

b

A significant association only at the level of haplotype, not single polymorphism.

c

A significant association only at the level of combined genotype of two or more variants. GPCR, G protein-coupled receptor; for details of the reported associations, see Supplementary Tables 2–5.

Among the polymorphisms positively associated with PPI, 22 (26.2%) are functional variants, i.e., related to the level of gene expression or the biological function of the protein products (as reported in the reviewed studies). For the remaining 62 (73.8%) variants, no direct functional consequences were reported. For P50 gating, 4 (10.8%) polymorphisms positively associated with this measure are functional and 33 (89.2%) are without known functional consequences. To examine the potential functional role of the positively associated variants, we carried out an in silico analysis using the HaploReg resource (117). The results of this analysis showed that a substantial proportion of polymorphisms that were associated with PPI (41 SNPs) and P50 gating (14 SNPs) overlap with regulatory motifs such as promoter/enhancer histone marks or DNase I hypersensitive sites (for a detailed description see Supplementary Tables 2–5).

Discussion

In this paper, we reviewed the available data on the relationship between genetic variability and sensory information filtering in humans. More specifically, we summarized, in a systematic manner, findings from genetic association studies published in peer-reviewed journals, examining the effect of common genetic variants on two well-established parameters of gating functions, PPI and P50/N100 ERP suppression (jointly referred to as P50 gating), deficits of which are considered as schizophrenia endophenotypes. We found that association with PPI or P50 gating was reported for variants located within or near 37 and 13 genes, respectively, which are involved in a variety of biological processes, mostly related to neurotransmission and neurodevelopment. However, most of the polymorphisms positively associated with PPI and/or P50 gating were examined in only one study or were not consistently replicated in other studies. According to our criteria for reliability (i.e., association confirmed in at least two independent samples and positive outcomes outnumbering negative results), only four polymorphisms within four genes for PPI (CHRNA3 rs1317286, COMT rs4680, HTR2A rs6311, and TCF4 rs9960767) and one polymorphism for P50 gating (CHRNA7 rs67158670) can be considered as reliable or consistent across the studies. Two of them (COMT rs4680 and TCF4 rs9960767) were identified as significantly associated with PPI also by Quednow et al. (47), who included 16 independent samples into a meta-analysis. Although a large number of reported associations were with non-coding polymorphisms, our analysis shows that a substantial proportion of them may play a role in gene expression by affecting the binding of transcription factors or chromatin remodeling. However, since enhancers may activate transcription of their target genes over considerable distances, up to hundreds or even thousands of kilobases, caution should be taken when making inferences about the functional connection between non-coding variants in these regions and target genes (118).

Replication of Association Results

From the 35 associations that were tested in more than one study, only 10 polymorphisms were reported to be significantly associated with gating in two or more studies. Low statistical power in some studies could increase the probability of false-negative results and unsuccessful replications. Although we excluded studies whose quality was evaluated as poor according to the Q-Genie scoring system, yet in 12 of 63 studies that fulfilled the criteria to be included in this review, sample size was lower than 50. Furthermore, a considerable number of negative replication results (14 of 30) come from samples that differed in ethnicity compared to the initial studies reporting positive results. Notably, in addition to genetic diversity, difference in startle response and PPI across ethnic groups (119) could decrease the number of successful replications. On the other hand, the non-replications seem not to be due to diversity in stimulation parameters since these did not substantially differ between almost all studies that had yielded discrepant outcomes. In the light of considerable heritability of gating functions (31, 3542), the low number of reliably assessed genetic associations clearly indicates that, despite the relatively large number of genetic studies, current knowledge on the genetic architecture of gating functions remains very limited. Next, we will focus our discussion on the variants/genes consistently associated with sensory and/or sensorimotor gating functions.

Catechol-O-Methyltransferase

Catechol-o-methyltransferase (COMT) is an enzyme degrading catecholamines. A single nucleotide G-A substitution at codon 158 results in a change from valine to methionine (Val158Met) causing a missense mutation with a lower metabolic activity of the enzyme. This polymorphism significantly affects dopamine turnover in the prefrontal cortex (PFC, Val allele associated with reduced PFC dopamine levels), PFC activity, and executive functions in healthy humans [for review see e.g., (120, 121)]. Numerous studies reported COMT Val158Met polymorphism to be related with liability to schizophrenia and several other mental disorders, but a recent meta-analysis did not confirm a significant association with schizophrenia (122). The Val allele was associated with weaker PPI in six of seven studies included in our review. In agreement with these reports, a study by Giakoumaki et al. (63) has shown that administration of a COMT inhibitor tolcapone increased PPI in Val allele carriers. As highlighted by the meta-analysis by Quednow et al. (47), the association of PPI with COMT Val158Met polymorphism is stronger in men than in women. Interestingly, a similar pattern of sex-dependent effects of this variation was also reported for response inhibition and linked with the activity of the PFC [(123), see also (124)]. Given the putative role of the PFC in the modulation of sensorimotor gating (125128), it could be speculated that the prefrontal circuitry is also involved in the sex-specific effects of COMT genotype on PPI, which remains to be established in future studies. The evidence for the association of COMT Val158Met with P50 gating is less consistent, as a significant association was reported in seven and non-significant in nine studied samples.

Another COMT polymorphism, rs165599, has not fulfilled our reliability criteria but was reported to be significantly associated with both PPI and P50 gating (only in one study each). Functional consequences of this variation are less clear, although there is evidence indicating its relationship with COMT mRNA levels in the brain of healthy humans, and IQ and the presence of psychotic symptoms in patients with 22q11 deletion syndrome (129, 130). A large case-control study reported its association with schizophrenia in women but not in men, suggesting that this SNP confers a sex-specific genetic component in schizophrenia (131). Notably, rs165599 and rs4680 are both part of a three-marker haplotype (together with rs2075507) that has been implicated in COMT protein level, PFC function in obsessive–compulsive disorder and attention-deficit hyperactivity disorder (129, 132, 133). This haplotype was significantly associated with P50 in a sample of patients with bipolar disorder (but not in healthy controls) (25). Its relationship with PPI has not been studied yet, as far as we are informed.

To sum up, there is considerable evidence that genetic variability of COMT affects gating functions, which fits with the proposed role of dopamine in the PFC (134). Interestingly, however, disruption of PPI following administration of dopamine agonists in rodents has been attributed to modulation of striatal rather than cortical circuitry (135, 136). In humans, on the other hand, the effects of dopamine agonists on PPI are less evident and reliable (137). Given the importance of PPI to study the neurobiology of schizophrenia in animal models, it would be desirable in future studies to shed more light on the specific roles of dopamine in cortical and striatal processing related to gating in humans and rodents.

Serotonin 2A Receptor

The HTR2A gene encodes a G-protein-coupled serotonin 2A receptor (5-HT2AR). In humans, 5-HT2AR is widely expressed throughout the brain with particularly high density in the neocortex (138). 5-HT2AR has been implicated in multiple brain functions such as learning, memory, and cognition [for review see (139)]. Importantly, several lines of evidence implicate 5-HT2AR in the pathophysiology of psychiatric disorders. First, genetic variants in the HTR2A gene and functional abnormalities of 5-HT2AR are associated with many psychiatric disorders including schizophrenia [for review see (140)]. Second, 5-HT2AR antagonists produce antipsychotic and antidepressant-like effects, whereas agonists have psychotomimetic properties including PPI-disruptive effects (140, 141). HTR2A rs6311 (also known as −1438A/G) is a functional SNP, which lies upstream of the HTR2A promoter region and alters its activity (142). Meta-analyses confirmed the association of this polymorphism with schizophrenia and obsessive–compulsive disorder (143145). Given the involvement of serotonin in multiple neurobiological processes, warranted are further studies of the role of 5-HT2AR in gating and its relationship with schizophrenia.

Nicotinic Acetylcholine Receptor

A lot of research implicates signaling via nicotinic acetylcholine receptor (nAChR) in gating, schizophrenia, and nicotine dependence [for review see (146)]. It is well established in rodents and humans that the agonist of nAChR nicotine enhances PPI and P50 gating [for review see (147)]. In humans, sensorimotor gating efficiency was found to be inversely related to nicotine dependence (148). Smoking and nicotine dependence are highly prevalent in schizophrenia, and it has been proposed that tobacco is used by the patients as self-medication to alleviate the symptoms, in particular the impairment of cognitive functions (149). Moreover, recent research indicates that nicotine dependence and schizophrenia may share a part of their genetic liability [for review see (150)]. Across the reviewed studies, consistent associations were reported between PPI and variation in CHRNA3 gene as well as between P50 gating and CHRFAM7A gene.

CHRNA3 is a part of a CHRNA5–CHRNA3–CHRNB4 gene cluster on chromosome 15 (15q25 region), encoding α5, α3, and β4 subunits of the nAChR, linked in previous studies to nicotine dependence as well as schizophrenia (151153). Our search specifically points to CHRNA3 rs1317286, which was reported to be associated with nicotine dependence in a GWAS (154). The analysis using HaploReg indicates that this SNP overlaps with enhancer histone marks and may thus play a role in CHRNA3 transcription. However, due to high linkage disequilibrium, it is difficult to determine causative variants in the CHRNA5–CHRNA3–CHRNB4 cluster, which is under complex and coordinated regulatory control (155). Interestingly, TCF4 (see below) has been identified as one of the regulators of gene expression at this locus (156).

CHRFAM7A is a partial duplication of a gene encoding α7 nAChR, CHRNA7. Translation of CHRFAM7A is low, but it seems to negatively regulate α7 nAChR function [for review see (157)]. The P50 gating-associated polymorphism of CHRFAM7A denoted as rs67158670 (or CHRFAM7AΔ2bp) is a 2-bp deletion in exon 6. This mutation causes a frameshift in translation, resulting in a truncated protein, which is even a more potent inhibitor of α7 nAChR (157). Reduced expression of CHRNA7 was found in the frontal cortex of schizophrenia patients post-mortem (158) and smoking counteracts this deficit (159). In addition to the association with P50 gating, studies reported association of CHRFAM7AΔ2bp with schizophrenia, bipolar disorder, and episodic memory [for review see (157)]. The impact of CHRFAM7AΔ2bp on brain development is debated, and research in this direction could bring new discoveries of the pathomechanistic links between gating deficits and schizophrenia.

Transcription Factor 4

The TCF4 gene codes for a basic helix–loop–helix protein, transcription factor 4, which belongs to a subclass of transcriptional regulators termed E-proteins. E-proteins bind to a specific promoter element known as the Ephrussi-box (E-box) to regulate transcription of target genes in various tissues including the brain [for review see (160)]. Although the precise physiological function of TCF4 is not yet fully understood, a recent study demonstrated that binding sites for TCF4 are present in a large number of genes involved in nervous system development, ion transport, and signal transduction (156). Moreover, this study also showed that TCF4 binding sites are found in many susceptibility genes implicated in common neurodevelopmental disorders including schizophrenia and autism spectrum disorders. Notably, several SNPs in TCF4 itself have been directly linked to schizophrenia, underscoring the possible role of this gene in schizophrenia pathogenesis (161). Our analysis points to a reliable association of TCF4 rs9960767 with PPI. Notably, Quednow et al. (90) reported that the effect of this polymorphism on PPI is moderated by smoking behavior, which fits with the regulatory role of TCF4 on the CHRNA5–CHRNA3–CHRNB4 cluster (156). The association of this variation with schizophrenia was confirmed at a meta-analytic and genome-wide level [for review see (162)]. TCF4 rs9960767 is located within intron 3 of the TCF4 gene and has no direct obvious functional consequences. Neither is there evidence of its linkage disequilibrium with other common non-synonymous polymorphisms or causal variants, which alter TCF4 mRNA expression in adult human brain (163). Williams et al. (163) suggested that rs9960767 may exert effects on TCF4 expression in a developmental context. Our findings support this notion as the HaploReg analysis indicates that rs9960767 may affect putative binding sites of transcription factors Foxa and STAT in the brain germinal matrix, which plays a critical role during brain development. All these findings indicate that sensorimotor gating deficit is a constituent of the neurodevelopmental insult, which is assumed to play a crucial role in the pathogenesis of schizophrenia (164).

Common Genetic Factors of Gating Functions

Four polymorphisms out of 45 variants studied so far were reported to be significantly associated with both PPI and P50 gating. Given our criteria of reliability, however, none of these associations was reliable for both measures. Evidence for common genetic mechanisms underlying both sensory and sensorimotor gating thus remains elusive. Although sensory and sensorimotor gating represent related concepts, the hallmark of which is inhibition, the relationship between PPI and P50 suppression is not fully understood. Correlation between the magnitude of PPI and P50 suppression seems weak since most studies found no significant relationship between the two measures (165171). Furthermore, PPI primarily relies on the processing in the brainstem and the basal ganglia, which is modulated by the cerebral cortex (125128, 135, 172176), while the sources of P50 ERP and P50 suppression are thought to be localized predominantly in the hippocampus, the temporal and the frontal lobes (167, 177179). Given the importance of PPI and P50 gating in psychiatry, further research is warranted to clarify the relationship between these two phenomena in more detail at both the cognitive/psychological and neurobiological levels.

Conclusion

Our review identified a considerable number of genetic variants associated with PPI or P50 gating in previous studies. However, a critical evaluation of the reports shows associations of only five polymorphisms (four for PPI and one for P50 gating) as consistently replicated across the studies. From these, only two variants (HTR2A rs6311 and TCF4 rs9960767, both associated with PPI) also show a reliable association with schizophrenia (meta-analytic or genome-wide evidence). Although deficits in sensory and sensorimotor gating are widely considered as important endophenotypes of schizophrenia, the evidence for the common genetic etiology of the impaired gating functions and schizophrenia thus remains limited, and further large-scale studies are warranted to advance our understanding of this complex problem.

Statements

Data availability statement

The original contributions presented in the study are included in the article/Supplementary Materials. Further inquiries can be directed to the corresponding author.

Author contributions

IR provided the concept and design of the study. DB and RR collected and analyzed the data. RR, IR, and DB wrote and revised the manuscript. All authors contributed to the article and approved the submitted version.

Acknowledgments

We thank Bronislava Brejová for assistance with enrichment analysis.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Supplementary material

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fpsyt.2020.550225/full#supplementary-material

References

  • 1.

    FreedmanRAdlerLEGerhardtGAWaldoMBakerNRoseGMet al. Neurobiological studies of sensory gating in schizophrenia. Schizophr Bull. (1987) 13:66978. 10.1093/schbul/13.4.669

  • 2.

    McGhieAChapmanJ. Disorders of attention and perception in early schizophrenia. Br J Med Psychol. (1961) 34:10316. 10.1111/j.2044-8341.1961.tb00936.x

  • 3.

    GrahamFK. The more or less startling effects of weak prestimulation. Psychophysiology. (1975) 12:23848. 10.1111/j.1469-8986.1975.tb01284.x

  • 4.

    BlumenthalTD. Presidential address 2014: the more-or-less interrupting effects of the startle response. Psychophysiology. (2015) 52:141731. 10.1111/psyp.12506

  • 5.

    GeyerMABraffDL. Startle habituation and sensorimotor gating in schizophrenia and related animal models. Schizophr Bull. (1987) 13:64368. 10.1093/schbul/13.4.643

  • 6.

    BraffDL. Gating and habituation of the startle reflex in schizophrenic patients. Arch Gen Psychiatry. (1992) 49:206. 10.1001/archpsyc.1992.01820030038005

  • 7.

    BraffDLLightGA. The use of neurophysiological endophenotypes to understand the genetic basis of schizophrenia. Dialogues Clin Neurosci. (2005) 7:12535. 10.31887/DCNS.2005.7.2/dlbraff

  • 8.

    BraffDLGeyerMA. Sensorimotor gating and schizophrenia. Arch Gen Psychiatry. (1990) 47:181. 10.1001/archpsyc.1990.01810140081011

  • 9.

    ArnfredSMChenACN. Exploration of somatosensory P50 gating in schizophrenia spectrum patients: reduced P50 amplitude correlates to social anhedonia. Psychiatry Res. (2004) 125:14760. 10.1016/j.psychres.2003.12.008

  • 10.

    DoluNSüerCÖzesmiÇ. A comparison of the different interpair intervals in the conditioning-testing P50 paradigms. Int J Psychophysiol. (2001) 41:26570. 10.1016/S0167-8760(01)00134-9

  • 11.

    JonesLAHillsPJDickKMJonesSPBrightP. Cognitive mechanisms associated with auditory sensory gating. Brain Cogn. (2016) 102:3345. 10.1016/j.bandc.2015.12.005

  • 12.

    LijffijtMLaneSDMeierSLBoutrosNNBurroughsSSteinbergJLet al. P50, N100, and P200 sensory gating: relationships with behavioral inhibition, attention, and working memory. Psychophysiology. (2009) 46:105968. 10.1111/j.1469-8986.2009.00845.x

  • 13.

    Brockhaus-DumkeASchultze-LutterFMuellerRTendolkarIBechdolfAPukropRet al. Sensory gating in schizophrenia: P50 and N100 gating in antipsychotic-free subjects at risk, first-episode, and chronic patients. Biol Psychiatry. (2008) 64:37684. 10.1016/j.biopsych.2008.02.006

  • 14.

    PowellSBWeberMGeyerMA. Genetic models of sensorimotor gating: relevance to neuropsychiatric disorders. Curr Top Behav Neurosci. (2012) 12:251318. 10.1007/7854_2011_195

  • 15.

    BlumenthalTDCuthbertBNFilionDLHackleySLippO V.Van BoxtelA. Committee report: Guidelines for human startle eyeblink electromyographic studies. Psychophysiology. (2005) 42:115. 10.1111/j.1469-8986.2005.00271.x

  • 16.

    FridlundAJCacioppoJT. Guidelines for human electromyographic research. Psychophysiology. (1986) 23:56789. 10.1111/j.1469-8986.1986.tb00676.x

  • 17.

    BramonERabe-HeskethSShamPMurrayRMFrangouS. Meta-analysis of the P300 and P50 waveforms in schizophrenia. Schizophr Res. (2004) 70:31529. 10.1016/j.schres.2004.01.004

  • 18.

    CadenheadKSGeyerMABraffDL. Impaired startle prepulse inhibition and habituation in patients with schizotypal personality disorder. Am J Psychiatry. (1993) 150:18627. 10.1176/ajp.150.12.1862

  • 19.

    ClementzBAGeyerMABraffDL. Poor P50 suppression among schizophrenia patients and their first- degree biological relatives. Am J Psychiatry. (1998) 155:16914. 10.1176/ajp.155.12.1691

  • 20.

    SwerdlowNRLightGAThomasMLSprockJCalkinsMEGreenMFet al. Deficient prepulse inhibition in schizophrenia in a multi-site cohort: internal replication and extension. Schizophr Res. (2018) 198:615. 10.1016/j.schres.2017.05.013

  • 21.

    HashimotoTShimizuEKoikeKOritaYSuzukiTKanaharaNet al. Deficits in auditory P50 inhibition in obsessive–compulsive disorder. Prog Neuro-Psychopharmacol Biol Psychiatry. (2008) 32:28896. 10.1016/j.pnpbp.2007.08.021

  • 22.

    HoenigKHochreinAQuednowBBMaierWWagnerM. Impaired prepulse inhibition of acoustic startle in obsessive-compulsive disorder. Biol Psychiatry. (2005) 57:11538. 10.1016/j.biopsych.2005.01.040

  • 23.

    SwerdlowNRKarbanBPloumYSharpRGeyerMAEastvoldA. Tactile prepuff inhibition of startle in children with Tourette's syndrome: in search of an “fMRI-friendly” startle paradigm. Biol Psychiatry. (2001) 50:57885. 10.1016/S0006-3223(01)01164-7

  • 24.

    PattersonJ VSandmanCARingAJinYBunneyJr. WE. An initial report of a new biological marker for bipolar disorder: P85 evoked brain potential. Bipolar Disord. (2009) 11:596609. 10.1111/j.1399-5618.2009.00734.x

  • 25.

    AncínICabranesJAVázquez-ÁlvarezBSantosJLSánchez-MorlaEGarcía-JiménezFernándezCBarabashA. Sensory gating deficit is associated with catechol-O-methyltransferase polymorphisms in bipolar disorder. World J Biol Psychiatry. (2011) 12:37684. 10.3109/15622975.2011.552192

  • 26.

    Sánchez-MorlaEMMateoJAparicioAGarcía-JiménezJiménezESantosJL. Prepulse inhibition in euthymic bipolar disorder patients in comparison with control subjects. Acta Psychiatr Scand. (2016) 134:3509. 10.1111/acps.12604

  • 27.

    MaoZBoQLiWWangZMaXWangC. Prepulse inhibition in patients with bipolar disorder: a systematic review and meta-analysis. BMC Psychiatry. (2019) 19:282. 10.1186/s12888-019-2271-8

  • 28.

    LijffijtMMoellerFGBoutrosNNSteinbergJLMeierSLLaneSDet al. Diminished P50, N100 and P200 auditory sensory gating in bipolar I disorder. Psychiatry Res. (2009) 167:191201. 10.1016/j.psychres.2008.04.001

  • 29.

    BraffDLGeyerMASwerdlowNR. Human studies of prepulse inhibition of startle: normal subjects, patient groups, and pharmacological studies. Psychopharmacology. (2001) 156:23458. 10.1007/s002130100810

  • 30.

    GeyerMA. The family of sensorimotor gating disorders: comorbidities or diagnostic overlaps?Neurotox Res. (2006) 10:21120. 10.1007/BF03033358

  • 31.

    GreenwoodTALightGASwerdlowNRCalkinsMEGreenMFGurREet al. Gating deficit heritability and correlation with increased clinical severity in schizophrenia patients with positive family history. Am J Psychiatry. (2016) 173:38591. 10.1176/appi.ajp.2015.15050605

  • 32.

    SchulzeKKHallM-HMcDonaldCMarshallNWalsheMMurrayRMet al. P50 auditory evoked potential suppression in bipolar disorder patients with psychotic features and their unaffected relatives. Biol Psychiatry. (2007) 62:1218. 10.1016/j.biopsych.2006.08.006

  • 33.

    CadenheadKSSwerdlowNRShaferKMDiazMBraffDL. Modulation of the startle response and startle laterality in relatives of schizophrenic patients and in subjects with schizotypal personality disorder: evidence of inhibitory deficits. Am J Psychiatry. (2000) 157:16608. 10.1176/appi.ajp.157.10.1660

  • 34.

    LiWMaoZBoQSunYWangZWangC. Prepulse inhibition in first-degree relatives of schizophrenia patients: a systematic review. Early Interv Psychiatry. (2020). [Epub ahead of print]. 10.1111/eip.13003

  • 35.

    GreenwoodTABraffDLLightGACadenheadKSCalkinsMEDobieDJet al. Initial heritability analyses of endophenotypic measures for schizophrenia: the consortium on the genetics of schizophrenia. Arch Gen Psychiatry. (2007) 64:124250. 10.1001/archpsyc.64.11.1242

  • 36.

    YoungDAWaldoMRutledgeJHFreedmanR. Heritability of inhibitory gating of the P50 auditory-evoked potential in monozygotic and dizygotic twins. Neuropsychobiology. (1996) 33:1137. 10.1159/000119260

  • 37.

    HallMHSchulzeKRijsdijkFPicchioniMEttingerUBramonEet al. Heritability and reliability of P300, P50 and duration mismatch negativity. Behav Genet. (2006) 36:84557. 10.1007/s10519-006-9091-6

  • 38.

    HasenkampWEpsteinMPGreenAWilcoxLBoshovenWLewisonBet al. Heritability of acoustic startle magnitude, prepulse inhibition, and startle latency in schizophrenia and control families. Psychiatry Res. (2010) 178:23643. 10.1016/j.psychres.2009.11.012

  • 39.

    SeidmanLJHellemannGNuechterleinKHGreenwoodTABraffDLCadenheadKSet al. Factor structure and heritability of endophenotypes in schizophrenia: findings from the Consortium on the Genetics of Schizophrenia (COGS-1). Schizophr Res. (2015) 163:739. 10.1016/j.schres.2015.01.027

  • 40.

    AnokhinAPHeathACMyersERalanoAWoodS. Genetic influences on prepulse inhibition of startle reflex in humans. Neurosci Lett. (2003) 353:458. 10.1016/j.neulet.2003.09.014

  • 41.

    AukesMFAlizadehBZSitskoornMMSeltenJ-PSinkeRJKemnerCet al. Finding suitable phenotypes for genetic studies of schizophrenia: heritability and segregation analysis. Biol Psychiatry. (2008) 64:12836. 10.1016/j.biopsych.2007.12.013

  • 42.

    AnokhinAPVedeniapinABHeathACKorzyukovOBoutrosNN. Genetic and environmental influences on sensory gating of mid-latency auditory evoked responses: a twin study. Schizophr Res. (2007) 89:3129. 10.1016/j.schres.2006.08.009

  • 43.

    FlintJMunafòMR. The endophenotype concept in psychiatric genetics. Psychol Med. (2007) 37:16380. 10.1017/S0033291706008750

  • 44.

    BraffDLFreedmanR. Endophenotypes in studies of the genetics of schizophrenia. In: DavisKLCharneyDCoyleJNemeroffC, editors. Neuropsychopharmacology: The Fifth Generation of Progress.Philadelphia, PA: Lippincott Williams & Wilkins (2002). p. 70316.

  • 45.

    GottesmanIIGouldTD. The endophenotype concept in psychiatry: etymology and strategic intentions. Am J Psychiatry. (2003) 160:63645. 10.1176/appi.ajp.160.4.636

  • 46.

    BraffDL. The importance of endophenotypes in schizophrenia research. Schizophr Res. (2015) 163:18. 10.1016/j.schres.2015.02.007

  • 47.

    QuednowBBEjebeKWagnerMGiakoumakiSGBitsiosPKumariVet al. Meta-analysis on the association between genetic polymorphisms and prepulse inhibition of the acoustic startle response. Schizophr Res. (2018) 198:529. 10.1016/j.schres.2017.12.011

  • 48.

    ShamseerLMoherDClarkeMGhersiDLiberatiAPetticrewMet al. Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015: elaboration and explanation. BMJ. (2015) 350:g7647. 10.1136/bmj.g7647

  • 49.

    SohaniZNMeyreDde SouzaRJJosephPGGandhiMDennisBBet al. Assessing the quality of published genetic association studies in meta-analyses: the quality of genetic studies (Q-Genie) tool. BMC Genet. (2015) 16:50. 10.1186/s12863-015-0211-2

  • 50.

    TangWHuJZhangHWuPHeH. Kappa coefficient: a popular measure of rater agreement. Shanghai Arch psychiatry. (2015) 27:627. 10.11919/j.issn.1002-0829.215010

  • 51.

    MoherDLiberatiATetzlaffJAltmanDGThe PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Med. (2009) 6:e1000097. 10.1371/journal.pmed1000097

  • 52.

    BertelsenBOranjeBMelchiorLFagerlundBWergeTMMikkelsenJDet al. Association Study of CHRNA7 promoter variants with sensory and sensorimotor gating in schizophrenia patients and healthy controls: a Danish Case-Control Study. NeuroMolecular Med. (2015) 17:42330. 10.1007/s12017-015-8371-9

  • 53.

    BräuerDStrobelAHenschTDiersKLeschK-PBrockeB. Genetic variation of serotonin receptor function affects prepulse inhibition of the startle. J Neural Transm. (2009) 116:60713. 10.1007/s00702-009-0222-0

  • 54.

    CabranesJAAncínISantosJLSÁnchez-MorlaEGarcía-JimÉnezLópez-IborJJet al. No effect of polymorphisms in the non-duplicated region of the CHRNA7 gene on sensory gating P50 ratios in patients with schizophrenia and bipolar disorder. Psychiatry Res. (2013) 205:2768. 10.1016/j.psychres.2012.08.015

  • 55.

    ComascoEGulinelloMHellgrenCSkalkidouASylvenSSundström-PoromaaI. Sleep duration, depression, and oxytocinergic genotype influence prepulse inhibition of the startle reflex in postpartum women. Eur Neuropsychopharmacol. (2016) 26:76776. 10.1016/J.EURONEURO.2016.01.002

  • 56.

    ComascoEHellgrenCOlivierJSkalkidouASundström PoromaaI. Supraphysiological hormonal status, anxiety disorders, and COMT Val/Val genotype are associated with reduced sensorimotor gating in women. Psychoneuroendocrinology. (2015) 60:21723. 10.1016/j.psyneuen.2015.06.019

  • 57.

    de KoningMBBootEBloemenOJNvan DuinEDAAbelKMde HaanLet al. Startle reactivity and prepulse inhibition of the acoustic startle response are modulated by catechol-O-methyl-transferase Val(158) Met polymorphism in adults with 22q11 deletion syndrome. J Psychopharmacol. (2012) 26:154860. 10.1177/0269881112456610

  • 58.

    de KoningMBvan DuinEDABootEBloemenOJNBakkerJAAbelKMet al. PRODH rs450046 and proline x COMT Val158Met interaction effects on intelligence and startle in adults with 22q11 deletion syndrome. Psychopharmacology. (2015) 232:311122. 10.1007/s00213-015-3971-5

  • 59.

    de la SalleSSmithDChoueiryJImpeyDPhilippeTDortHet al. Effects of COMT genotype on sensory gating and its modulation by nicotine: differences in low and high P50 suppressors. Neuroscience. (2013) 241:14756. 10.1016/j.neuroscience.2013.03.029

  • 60.

    DemilyCLouchart-de-la-ChapelleSNkamIRamozNDenisePNicolasAet al. Does COMT val158met polymorphism influence P50 sensory gating, eye tracking or saccadic inhibition dysfunctions in schizophrenia? Psychiatry Res. (2016) 246:73844. 10.1016/j.psychres.2016.07.066

  • 61.

    FlomenRHShaikhMWalsheMSchulzeKHallM-HPicchioniMet al. Association between the 2-bp deletion polymorphism in the duplicated version of the alpha7 nicotinic receptor gene and P50 sensory gating. Eur J Hum Genet. (2013) 21:7681. 10.1038/ejhg.2012.81

  • 62.

    GajewskaABlumenthalTDWinterBHerrmannMJConzelmannAMühlbergerAet al. Effects of ADORA2A gene variation and caffeine on prepulse inhibition: a multi-level risk model of anxiety. Prog Neuro Psychopharmacol Biol Psychiatry. (2013) 40:11521. 10.1016/j.pnpbp.2012.08.008

  • 63.

    GiakoumakiSGRoussosPBitsiosP. Improvement of prepulse inhibition and executive function by the COMT inhibitor tolcapone depends on COMT Val158Met polymorphism. Neuropsychopharmacology. (2008) 33:305868. 10.1038/npp.2008.82

  • 64.

    GreenbaumLLevinRLererEAlkelaiAKohnYHeresco-LevyUet al. Association of Reelin (RELN) single nucleotide polymorphism rs7341475 with prepulse inhibition in the Jewish Israeli population. Biol Psychiatry. (2011) 69:e178. 10.1016/j.biopsych.2010.09.059

  • 65.

    GreenwoodTALazzeroniLCMaihoferAXSwerdlowNRCalkinsMEFreedmanRet al. Genome-wide Association of Endophenotypes for Schizophrenia From the Consortium on the Genetics of Schizophrenia (COGS) Study. JAMA Psychiatry. (2019) 76:1274. 10.1001/jamapsychiatry.2019.2850

  • 66.

    GreenwoodTALazzeroniLCMurraySSCadenheadKSCalkinsMEDobieDJet al. Analysis of 94 candidate genes and 12 endophenotypes for schizophrenia from the Consortium on the Genetics of Schizophrenia. Am J Psychiatry. (2011) 168:93046. 10.1176/appi.ajp.2011.10050723

  • 67.

    GreenwoodTALightGASwerdlowNRRadantADBraffDL. Association analysis of 94 candidate genes and schizophrenia-related endophenotypes. PLoS ONE. (2012) 7:e29630. 10.1371/journal.pone.0029630

  • 68.

    HallM-HChenC-YCohenBMSpencerKMLevyDLÖngürDet al. Genomewide association analyses of electrophysiological endophenotypes for schizophrenia and psychotic bipolar disorders: a preliminary report. Am J Med Genet Part B Neuropsychiatr Genet. (2015) 168:15161. 10.1002/ajmg.b.32298

  • 69.

    HallM-HLevyDLSalisburyDFHaddadSGallagherPLohanMet al. Neurophysiologic effect of GWAS derived schizophrenia and bipolar risk variants. Am J Med Genet Part B Neuropsychiatr Genet. (2014) 165:918. 10.1002/ajmg.b.32212

  • 70.

    HashimotoROhiKYasudaYFukumotoMYamamoriHTakahashiHet al. Variants of the RELA gene are associated with schizophrenia and their startle responses. Neuropsychopharmacology. (2011) 36:192131. 10.1038/npp.2011.78

  • 71.

    HesslDBerry-KravisECordeiroLYuhasJOrnitzEMCampbellAet al. Prepulse inhibition in fragile X syndrome: feasibility, reliability, and implications for treatment. Am J Med Genet B Neuropsychiatr Genet. (2009) 150B:54553. 10.1002/ajmg.b.30858

  • 72.

    HokyoAKanazawaTUenishiHTsutsumiAKawashigeSKikuyamaHet al. Habituation in prepulse inhibition is affected by a polymorphism on the NMDA receptor 2B subunit gene (GRIN2B). Psychiatr Genet. (2010) 20:1918. 10.1097/YPG.0b013e32833a201d

  • 73.

    HongLEWonodiIStineOCMitchellBDThakerGK. Evidence of missense mutations on the neuregulin 1 gene affecting function of prepulse inhibition. Biol Psychiatry. (2008) 63:1723. 10.1016/j.biopsych.2007.05.011

  • 74.

    KirenskayaAVStorozhevaZIKolobovVVSherstnevVV. The acoustic startle response and polymorphism of the gene for catechol-O-methyltransferase in the norm and in schizophrenia. Neurochem J. (2015) 9:7683. 10.1134/S1819712415010031

  • 75.

    KnottVMillarAFisherDAlbertP. Effects of nicotine on the amplitude and gating of the auditory P50 and its influence by dopamine D2 receptor gene polymorphism. Neuroscience. (2010) 166:14556. 10.1016/j.neuroscience.2009.11.053

  • 76.

    LennertzLQuednowBBSchuhmacherAPetrovskyNFrommannISchulze-RauschenbachSet al. The functional coding variant Asn107Ile of the neuropeptide S receptor gene (NPSR1) is associated with schizophrenia and modulates verbal memory and the acoustic startle response. Int J Neuropsychopharmacol. (2012) 15:120515. 10.1017/S1461145711001623

  • 77.

    LeonardSGaultJHopkinsJLogelJVianzonRShortMet al. Association of promoter variants in the α7 nicotinic acetylcholine receptor subunit gene with an inhibitory deficit found in schizophrenia. Arch Gen Psychiatry. (2002) 59:108596. 10.1001/archpsyc.59.12.1085

  • 78.

    LevinRHeresco-LevyUBachner-MelmanRIsraelSShalevIEbsteinRP. Association between arginine vasopressin 1a receptor (AVPR1a) promoter region polymorphisms and prepulse inhibition. Psychoneuroendocrinology. (2009) 34:9018. 10.1016/j.psyneuen.2008.12.014

  • 79.

    LiuXHongXChanRCKKongFPengZWanXet al. Association study of polymorphisms in the alpha 7 nicotinic acetylcholine receptor subunit and catechol-o-methyl transferase genes with sensory gating in first-episode schizophrenia. Psychiatry Res. (2013) 209:4318. 10.1016/j.psychres.2013.03.027

  • 80.

    LuBYMartinKEEdgarJCSmithAKLewisSFEscamillaMAet al. Effect of catechol O-methyltransferase val(158)met polymorphism on the p50 gating endophenotype in schizophrenia. Biol Psychiatry. (2007) 62:8225. 10.1016/j.biopsych.2006.11.030

  • 81.

    MajicTRentzschJGudlowskiYEhrlichSJuckelGSanderTet al. COMT Val108/158Met genotype modulates human sensory gating. Neuroimage. (2011) 55:81824. 10.1016/j.neuroimage.2010.12.031

  • 82.

    MaoQTanY-LLuoX-GTianLWangZ-RTanS-PChenSYangG-GAnH-MYangF-Det al. Association of catechol-O-methyltransferase Val 108/158 Met genetic polymorphism with schizophrenia, P50 sensory gating, and negative symptoms in a Chinese population. Psychiatry Res. (2016) 242:2716. 10.1016/j.psychres.2016.04.029

  • 83.

    MatsunoHOhiKHashimotoRYamamoriHYasudaYFujimotoMet al. A Naturally occurring null variant of the NMDA type glutamate receptor NR3B subunit is a risk factor of schizophrenia. PLoS ONE. (2015) 10:e0116319. 10.1371/journal.pone.0116319

  • 84.

    MillarASmithDChoueiryJFisherDAlbertPKnottV. The moderating role of the dopamine transporter 1 gene on P50 sensory gating and its modulation by nicotine. Neuroscience. (2011) 180:14856. 10.1016/j.neuroscience.2011.02.008

  • 85.

    MontagCHartmannPMerzMBurkCReuterM. D2 receptor density and prepulse inhibition in humans: negative findings from a molecular genetic approach. Behav Brain Res. (2008) 187:42832. 10.1016/j.bbr.2007.10.006

  • 86.

    NotzonSVennewaldNGajewskaAKlahnALDiemerJWinterBet al. Is prepulse modification altered by continuous theta burst stimulation? DAT1 genotype and motor threshold interact on prepulse modification following brain stimulation. Eur Arch Psychiatry Clin Neurosci. (2017) 267:76779. 10.1007/s00406-017-0786-x

  • 87.

    PerkinsKALermanCCoddingtonSJettonCKarelitzJLWilsonAet al. Gene and gene by sex associations with initial sensitivity to nicotine in nonsmokers. Behav Pharmacol. (2008) 19:63040. 10.1097/FBP.0b013e32830c3621

  • 88.

    PetrovskyNEttingerUKesslerHMössnerRWolfsgruberSDahmenNet al. The effect of nicotine on sensorimotor gating is modulated by a CHRNA3 polymorphism. Psychopharmacology. (2013) 229:3140. 10.1007/s00213-013-3081-1

  • 89.

    PetrovskyNQuednowBBEttingerUSchmechtigAMössnerRCollierDAet al. Sensorimotor gating is associated with CHRNA3 polymorphisms in schizophrenia and healthy volunteers. Neuropsychopharmacology. (2010) 35:142939. 10.1038/npp.2010.12

  • 90.

    QuednowBBBrinkmeyerJMobascherANothnagelMMussoFGründerGet al. Schizophrenia risk polymorphisms in the TCF4 gene interact with smoking in the modulation of auditory sensory gating. Proc Natl Acad Sci USA. (2012) 109:62716. 10.1073/pnas.1118051109

  • 91.

    QuednowBBEttingerUMössnerRRujescuDGieglingICollierDAet al. The schizophrenia risk allele C of the TCF4 rs9960767 polymorphism disrupts sensorimotor gating in schizophrenia spectrum and healthy volunteers. J Neurosci. (2011) 31:668491. 10.1523/JNEUROSCI.0526-11.2011

  • 92.

    QuednowBBKühnK-UMössnerRSchwabSGSchuhmacherAMaierWet al. Sensorimotor gating of schizophrenia patients is influenced by 5-HT2A receptor polymorphisms. Biol Psychiatry. (2008) 64:4347. 10.1016/j.biopsych.2008.02.019

  • 93.

    QuednowBBSchmechtigAEttingerUPetrovskyNCollierDAVollenweiderFXet al. Sensorimotor gating depends on polymorphisms of the serotonin-2A receptor and catechol-O-methyltransferase, but Not on Neuregulin-1 Arg38Gln genotype: a replication study. Biol Psychiatry. (2009) 66:61420. 10.1016/j.biopsych.2009.05.007

  • 94.

    QuednowBBWagnerMMössnerRMaierWKühnK-UU. Sensorimotor gating of schizophrenia patients depends on catechol o-methyltransferase val158met polymorphism. Schizophr Bull. (2010) 36:3416. 10.1093/schbul/sbn088

  • 95.

    RauxGBonnet-BrilhaultFLouchartSHouyEGantierRLevillainDet al. The -2 bp deletion in exon 6 of the “alpha 7-like” nicotinic receptor subunit gene is a risk factor for the P50 sensory gating deficit. Mol Psychiatry. (2002) 7:100611. 10.1038/sj.mp.4001140

  • 96.

    RoussosPGiakoumakiSGAdamakiEBitsiosP. The influence of schizophrenia-related neuregulin-1 polymorphisms on sensorimotor gating in healthy males. Biol Psychiatry. (2011) 69:47986. 10.1016/j.biopsych.2010.09.009

  • 97.

    RoussosPGiakoumakiSGAdamakiEGeorgakopoulosAAnastasiosGRobakisNKet al. The association of schizophrenia risk D-amino acid oxidase polymorphisms with sensorimotor gating, working memory and personality in healthy males. Neuropsychopharmacology. (2011) 36:167788. 10.1038/npp.2011.49

  • 98.

    RoussosPGiakoumakiSGBitsiosP. A risk PRODH haplotype affects sensorimotor gating, memory, schizotypy, and anxiety in healthy male subjects. Biol Psychiatry. (2009) 65:106370. 10.1016/j.biopsych.2009.01.003

  • 99.

    RoussosPGiakoumakiSGBitsiosP. The dopamine D3 receptor Ser9Gly polymorphism modulates prepulse inhibition of the acoustic startle reflex. Biol Psychiatry. (2008) 64:23540. 10.1016/j.biopsych.2008.01.020

  • 100.

    RoussosPGiakoumakiSGBitsiosP. Tolcapone effects on gating, working memory, and mood interact with the synonymous catechol-O-methyltransferase rs4818c/g polymorphism. Biol Psychiatry. (2009) 66:9971004. 10.1016/j.biopsych.2009.07.008

  • 101.

    RoussosPGiakoumakiSGGeorgakopoulosARobakisNKBitsiosP. The CACNA1C and ANK3 risk alleles impact on affective personality traits and startle reactivity but not on cognition or gating in healthy males. Bipolar Disord. (2011) 13:2509. 10.1111/j.1399-5618.2011.00924.x

  • 102.

    RoussosPGiakoumakiSGRogdakiMPavlakisSFrangouSBitsiosP. Prepulse inhibition of the startle reflex depends on the catechol O-methyltransferase Val158Met gene polymorphism. Psychol Med. (2008) 38:16518. 10.1017/S0033291708002912

  • 103.

    RoussosPGiakoumakiSGZourarakiCFullardJFKaragiorgaVETsapakisEMet al. The relationship of common risk variants and polygenic risk for schizophrenia to sensorimotor gating. Biol Psychiatry. (2016) 79:98896. 10.1016/j.biopsych.2015.06.019

  • 104.

    RoussosPKatselPDavisKLGiakoumakiSGLenczTMalhotraAKet al. Convergent findings for abnormalities of the NF-κB signaling pathway in schizophrenia. Neuropsychopharmacology. (2013) 38:5339. 10.1038/npp.2012.215

  • 105.

    RovnýRMarkoMKatinaSMurínováJRohárikováVCimrováBet al. Association between genetic variability of neuronal nitric oxide synthase and sensorimotor gating in humans. Nitric Oxide. (2018) 80:326. 10.1016/J.NIOX.2018.08.002

  • 106.

    SchuhmacherABeckerTRujescuDQuednowBBLennertzLWagnerMet al. Investigation of tryptophan hydroxylase 2 (TPH2) in schizophrenia and in the response to antipsychotics. J Psychiatr Res. (2012) 46:107380. 10.1016/j.jpsychires.2012.04.021

  • 107.

    ShaikhMHallM-HSchulzeKDuttAWalsheMWilliamsIet al. Do COMT, BDNF and NRG1 polymorphisms influence P50 sensory gating in psychosis?Psychol Med. (2011) 41:26376. 10.1017/S003329170999239X

  • 108.

    ShiJWangZTanYFanHAnHZuoLet al. CHRNA4 was associated with prepulse inhibition of schizophrenia in Chinese: a pilot study. Cogn Neuropsychiatry. (2016) 21:15667. 10.1080/13546805.2016.1155437

  • 109.

    VogtJYangJMobascherAChengJLiYLiuXet al. Molecular cause and functional impact of altered synaptic lipid signaling due to a prg-1 gene SNP. EMBO Mol Med. (2016) 8:2538. 10.15252/emmm.201505677

  • 110.

    VölterCRiedelMWöstmannNAichertDSLoboSCostaAet al. Sensorimotor gating and D2 receptor signalling: evidence from a molecular genetic approach. Int J Neuropsychopharmacol. (2012) 15:142740. 10.1017/S1461145711001787

  • 111.

    VorstmanJASTuretskyBISijmens-MorcusMEJde SainMGDorlandBSprongMet al. Proline affects brain function in 22q11DS children with the low activity COMT158 allele. Neuropsychopharmacology. (2009) 34:73946. 10.1038/npp.2008.132

  • 112.

    WonodiIMcMahonRPKrishnaNMitchellBDLiuJGlassmanMet al. Influence of kynurenine 3-monooxygenase (KMO) gene polymorphism on cognitive function in schizophrenia. Schizophr Res. (2014) 160:807. 10.1016/j.schres.2014.10.026

  • 113.

    ZarchiOCarmelMAvniCAttiasJFrischAMichaelovskyEet al. Schizophrenia-like neurophysiological abnormalities in 22q11.2 deletion syndrome and their association to COMT and PRODH genotypes. J Psychiatr Res. (2013) 47:16239. 10.1016/j.jpsychires.2013.07.004

  • 114.

    MiHMuruganujanAEbertDHuangXThomasPD. PANTHER version 14: more genomes, a new PANTHER GO-slim and improvements in enrichment analysis tools. Nucleic Acids Res. (2019) 47:D41926. 10.1093/nar/gky1038

  • 115.

    The Gene Ontology Consortium. The gene ontology resource: 20 years and still GOing strong. Nucleic Acids Res. (2019) 47:D3308. 10.1093/nar/gky1055

  • 116.

    AshburnerMBallCABlakeJABotsteinDButlerHCherryJMet al. Gene ontology: tool for the unification of biology. the gene ontology consortium. Nat Genet. (2000) 25:259. 10.1038/75556

  • 117.

    WardLDKellisM. HaploReg: a resource for exploring chromatin states, conservation, and regulatory motif alterations within sets of genetically linked variants. Nucleic Acids Res. (2012) 40:D9304. 10.1093/nar/gkr917

  • 118.

    BulgerMGroudineM. Functional and mechanistic diversity of distal transcription enhancers. Cell. (2011) 144:32739. 10.1016/j.cell.2011.01.024

  • 119.

    HasenkampWNorrholmSDGreenALewisonBBoshovenWKeyesMet al. Differences in startle reflex and prepulse inhibition in European-Americans and African-Americans. Psychophysiology. (2008) 45:87682. 10.1111/j.1469-8986.2008.00680.x

  • 120.

    TunbridgeEMHarrisonPJWeinbergerDR. Catechol-o-methyltransferase, cognition, and psychosis: Val158Met and beyond. Biol Psychiatry. (2006) 60:14151. 10.1016/j.biopsych.2005.10.024

  • 121.

    WitteAVFlöelA. Effects of COMT polymorphisms on brain function and behavior in health and disease. Brain Res Bull. (2012) 88:41828. 10.1016/j.brainresbull.2011.11.012

  • 122.

    TaylorS. Association between COMT Val158Met and psychiatric disorders: a comprehensive meta-analysis. Am J Med Genet B Neuropsychiatr Genet. (2018) 177:199210. 10.1002/ajmg.b.32556

  • 123.

    WhiteTPLothERubiaKKrabbendamLWhelanRBanaschewskiTet al. Sex differences in COMT polymorphism effects on prefrontal inhibitory control in adolescence. Neuropsychopharmacology. (2014) 39:25609. 10.1038/npp.2014.107

  • 124.

    TunbridgeEMHarrisonPJ. Importance of the COMT gene for sex differences in brain function and predisposition to psychiatric disorders. Curr Top Behav Neurosci. (2011) 8:11940. 10.1007/7854_2010_97

  • 125.

    KumariVAntonovaEZachariahEGaleaAAasenIEttingerUet al. Structural brain correlates of prepulse inhibition of the acoustic startle response in healthy humans. Neuroimage. (2005) 26:10528. 10.1016/j.neuroimage.2005.03.002

  • 126.

    KumariVGrayJAGeyerMAffytcheDSoniWMitterschiffthalerMTet al. Neural correlates of tactile prepulse inhibition: a functional MRI study in normal and schizophrenic subjects. Psychiatry Res Neuroimaging. (2003) 122:99113. 10.1016/S0925-4927(02)00123-3

  • 127.

    HazlettEABuchsbaumMSHaznedarMMSingerMBGermansMKSchnurDBet al. Prefrontal cortex glucose metabolism and startle eyeblink modification abnormalities in unmedicated schizophrenia patients. Psychophysiology. (1998) 35:18698. 10.1111/1469-8986.3520186

  • 128.

    SwerdlowNRKoobGF. Dopamine, schizophrenia, mania, and depression: toward a unified hypothesis of cortico-striatopallido-thalamic function. Behav Brain Sci. (1987) 10:197208. 10.1017/S0140525X00047488

  • 129.

    GothelfDLawAJFrischAChenJZarchiOMichaelovskyEet al. Biological effects of COMT haplotypes and psychosis risk in 22q11.2 deletion syndrome. Biol Psychiatry. (2014) 75:40613. 10.1016/j.biopsych.2013.07.021

  • 130.

    BrayNJBucklandPRWilliamsNMWilliamsHJNortonNOwenMJet al. A haplotype implicated in schizophrenia susceptibility is associated with reduced COMT expression in human brain. Am J Hum Genet. (2003) 73:15261. 10.1086/376578

  • 131.

    ShifmanSBronsteinMSternfeldMPisanté-ShalomALev-LehmanEWeizmanAet al. A highly significant association between a COMT haplotype and schizophrenia. Am J Hum Genet. (2002) 71:1296302. 10.1086/344514

  • 132.

    Meyer-LindenbergANicholsTCallicottJHDingJKolachanaBBuckholtzJet al. Impact of complex genetic variation in COMT on human brain function. Mol Psychiatry. (2006) 11:86777. 10.1038/sj.mp.4001860

  • 133.

    MichaelovskyEGothelfDKorostishevskyMFrischABurgMCarmelMet al. Association between a common haplotype in the COMT gene region and psychiatric disorders in individuals with 22q11.2DS. Int J Neuropsychopharmacol. (2008) 11:35163. 10.1017/S1461145707008085

  • 134.

    OttTNiederA. Dopamine and cognitive control in prefrontal cortex. Trends Cogn Sci. (2019) 23:21334. 10.1016/j.tics.2018.12.006

  • 135.

    SwerdlowNRGeyerMABraffDL. Neural circuit regulation of prepulse inhibition of startle in the rat: current knowledge and future challenges. Psychopharmacology. (2001) 156:194215. 10.1007/s002130100799

  • 136.

    SwerdlowNRMansbachRSGeyerMAPulvirentiLKoobGFBraffDL. Amphetamine disruption of prepulse inhibition of acoustic startle is reversed by depletion of mesolimbic dopamine. Psychopharmacology. (1990) 100:4136. 10.1007/BF02244616

  • 137.

    SwerdlowNEastvoldAKarbanBPloumYStephanyNGeyerMet al. Dopamine agonist effects on startle and sensorimotor gating in normal male subjects: time course studies. Psychopharmacology. (2002) 161:189201. 10.1007/s00213-002-1040-3

  • 138.

    BurnetPWEastwoodSLLaceyKHarrisonPJ. The distribution of 5-HT1A and 5-HT2A receptor mRNA in human brain. Brain Res. (1995) 676:15768. 10.1016/0006-8993(95)00104-X

  • 139.

    ZhangGStackmanRWJr. The role of serotonin 5-HT2A receptors in memory and cognition. Front Pharmacol. (2015) 6:225. 10.3389/fphar.2015.00225

  • 140.

    QuednowBBGeyerMAHalberstadtAL. Serotonin and schizophrenia. Handb Behav Neurosci. (2020) 31:71143. 10.1016/B978-0-444-64125-0.00039-6

  • 141.

    MoravcíkováLCsatlósováKDurišováBOndácováKPavlovicováMLacinováLDremencovE. Role of serotonin-2A receptors in pathophysiology and treatment of depression. In: GuiardBDi GiovanniG, editors. 5-HT2A Receptors in the Central Nervous System. Cham: Springer International Publishing (2018). p. 20530.

  • 142.

    ParsonsMJD'SouzaUMArranzM-JKerwinRWMakoffAJ. The−1438A/G polymorphism in the 5-hydroxytryptamine type 2A receptor gene affects promoter activity. Biol Psychiatry. (2004) 56:40610. 10.1016/j.biopsych.2004.06.020

  • 143.

    GuLLongJYanYChenQPanRXieXet al. HTR2A −1438A/G polymorphism influences the risk of schizophrenia but not bipolar disorder or major depressive disorder: a meta-analysis. J Neurosci Res. (2013) 91:62333. 10.1002/jnr.23180

  • 144.

    FarrellMSWergeTSklarPOwenMJOphoffRAO'DonovanMCet al. Evaluating historical candidate genes for schizophrenia. Mol Psychiatry. (2015) 20:55562. 10.1038/mp.2015.16

  • 145.

    TaylorS. Disorder-specific genetic factors in obsessive-compulsive disorder: a comprehensive meta-analysis. Am J Med Genet B Neuropsychiatr Genet. (2016) 171:32532. 10.1002/ajmg.b.32407

  • 146.

    MackowickKMBarrMSWingVCRabinRAOuellet-PlamondonCGeorgeTP. Neurocognitive endophenotypes in schizophrenia: modulation by nicotinic receptor systems. Prog Neuropsychopharmacol Biol Psychiatry. (2014) 52:7985. 10.1016/j.pnpbp.2013.07.010

  • 147.

    KumariVPostmaP. Nicotine use in schizophrenia: the self medication hypotheses. Neurosci Biobehav Rev. (2005) 29:102134. 10.1016/j.neubiorev.2005.02.006

  • 148.

    KumariVGrayJA. Smoking withdrawal, nicotine dependence and prepulse inhibition of the acoustic startle reflex. Psychopharmacology. (1999) 141:115. 10.1007/s002130050800

  • 149.

    DalackGWHealyDJMeador-WoodruffJH. Nicotine dependence in schizophrenia: clinical phenomena and laboratory findings. Am J Psychiatry. (1998) 155:1490501. 10.1176/ajp.155.11.1490

  • 150.

    QuigleyHMacCabeJH. The relationship between nicotine and psychosis. Ther Adv Psychopharmacol. (2019) 9:204512531985996. 10.1177/2045125319859969

  • 151.

    BrunzellDHStaffordAMDixonCI. Nicotinic receptor contributions to smoking: insights from human studies and animal models. Curr Addict Reports. (2015) 2:3346. 10.1007/s40429-015-0042-2

  • 152.

    JacksonKJFanousAHChenJKendlerKSChenX. Variants in the 15q25 gene cluster are associated with risk for schizophrenia and bipolar disorder. Psychiatr Genet. (2013) 23:20. 10.1097/YPG.0b013e32835bd5f1

  • 153.

    WareJJMunafòMR. Genetics of smoking behaviour. Curr Top Behav Neurosci. (2015) 23:1936. 10.1007/978-3-319-13665-3_2

  • 154.

    BerrettiniWYuanXTozziFSongKFrancksCChilcoatHet al. Alpha-5/alpha-3 nicotinic receptor subunit alleles increase risk for heavy smoking. Mol Psychiatry. (2008) 13:36873. 10.1038/sj.mp.4002154

  • 155.

    BarrieESHartmannKLeeS-HFraterJTSewerynMWangDet al. The CHRNA5/CHRNA3/CHRNB4 nicotinic receptor regulome: genomic architecture, regulatory variants, and clinical associations. Hum Mutat. (2017) 38:1129. 10.1002/humu.23135

  • 156.

    ForrestMPHillMJKavanaghDHTanseyKEWaiteAJBlakeDJ. The psychiatric risk gene transcription factor 4 (TCF4) regulates neurodevelopmental pathways associated with schizophrenia, autism, and intellectual disability. Schizophr Bull. (2018) 44:110010. 10.1093/schbul/sbx164

  • 157.

    SinkusMLGrawSFreedmanRRossRGLesterHALeonardS. The human CHRNA7 and CHRFAM7A genes: a review of the genetics, regulation, and function. Neuropharmacology. (2015) 96:27488. 10.1016/j.neuropharm.2015.02.006

  • 158.

    GuanZZZhangXBlennowKNordbergA. Decreased protein level of nicotinic receptor alpha7 subunit in the frontal cortex from schizophrenic brain. Neuroreport. (1999) 10:177982. 10.1097/00001756-199906030-00028

  • 159.

    MexalSBergerRLogelJRossRGFreedmanRLeonardS. Differential regulation of alpha7 nicotinic receptor gene (CHRNA7) expression in schizophrenic smokers. J Mol Neurosci. (2010) 40:18595. 10.1007/s12031-009-9233-4

  • 160.

    ForrestMPHillMJQuantockAJMartin-RendonEBlakeDJ. The emerging roles of TCF4 in disease and development. Trends Mol Med. (2014) 20:32231. 10.1016/j.molmed.2014.01.010

  • 161.

    RipkeSNealeBMCorvinAWaltersJTRFarhK-HHolmansPAet al. Biological insights from 108 schizophrenia-associated genetic loci. Nature. (2014) 511:4217. 10.1038/nature13595

  • 162.

    QuednowBBBrzózkaMMRossnerMJ. Transcription factor 4 (TCF4) and schizophrenia: integrating the animal and the human perspective. Cell Mol Life Sci. (2014) 71:281535. 10.1007/s00018-013-1553-4

  • 163.

    WilliamsHJMoskvinaVSmithRLDwyerSRussoGOwenMJet al. Association between TCF4 and schizophrenia does not exert its effect by common nonsynonymous variation or by influencing cis-acting regulation of mRNA expression in adult human brain. Am J Med Genet B Neuropsychiatr Genet. (2011) 156B:7814. 10.1002/ajmg.b.31219

  • 164.

    BirnbaumRWeinbergerDR. Genetic insights into the neurodevelopmental origins of schizophrenia. Nat Rev Neurosci. (2017) 18:72740. 10.1038/nrn.2017.125

  • 165.

    BrennerCAEdwardsCRCarrollCAKieffaberPDHetrickWP. P50 and acoustic startle gating are not related in healthy participants. Psychophysiology. (2004) 41:7028. 10.1111/j.1469-8986.2004.00206.x

  • 166.

    BraffDLLightGASwerdlowNR. Prepulse inhibition and P50 suppression are both deficient but not correlated in schizophrenia patients. Biol Psychiatry. (2007) 61:12047. 10.1016/j.biopsych.2006.08.015

  • 167.

    OranjeBGeyerMABockerKBELeon KenemansJVerbatenMN. Prepulse inhibition and P50 suppression: commonalities and dissociations. Psychiatry Res. (2006) 143:14758. 10.1016/j.psychres.2005.11.002

  • 168.

    CadenheadKSLightGAGeyerMAMcDowellJEBraffDL. Neurobiological measures of schizotypal personality disorder: defining an inhibitory endophenotype?Am J Psychiatry. (2002) 159:86971. 10.1176/appi.ajp.159.5.869

  • 169.

    SchwarzkopfSBLambertiJSSmithDA. Concurrent assessment of acoustic startle and auditory P50 evoked potential measures of sensory inhibition. Biol Psychiatry. (1993) 33:81528. 10.1016/0006-3223(93)90023-7

  • 170.

    EllenbroekBAvan LuijtelaarGFrenkenMCoolsAR. Sensory gating in rats: lack of correlation between auditory evoked potential gating and prepulse inhibition. Schizophr Bull. (1999) 25:77788. 10.1093/oxfordjournals.schbul.a033418

  • 171.

    OranjeBvan BerckelBNKemnerCvan ReeJMKahnRSVerbatenMN. P50 suppression and prepulse inhibition of the startle reflex in humans: a correlational study. Biol Psychiatry. (1999) 45:88390. 10.1016/S0006-3223(98)00128-0

  • 172.

    KochM. The neurobiology of startle. Prog Neurobiol. (1999) 59:10728. 10.1016/S0301-0082(98)00098-7

  • 173.

    KochMKungelMHerbertH. Cholinergic neurons in the pedunculopontine tegmental nucleus are involved in the mediation of prepulse inhibition of the acoustic startle response in the rat. Exp Brain Res. (1993) 97:7182. 10.1007/BF00228818

  • 174.

    SwerdlowNRLightGA. Sensorimotor gating deficits in schizophrenia: advancing our understanding of the phenotype, its neural circuitry and genetic substrates. Schizophr Res. (2018) 198:15. 10.1016/j.schres.2018.02.042

  • 175.

    SchwabeKKraussJK. What rodent models of deep brain stimulation can teach us about the neural circuit regulation of prepulse inhibition in neuropsychiatric disorders. Schizophr Res. (2018) 198:4551. 10.1016/j.schres.2017.06.033

  • 176.

    SwerdlowNRBraffDLGeyerMA. Animal models of deficient sensorimotor gating: what we know, what we think we know, and what we hope to know soon. Behav Pharmacol. (2000) 11:185204. 10.1097/00008877-200006000-00002

  • 177.

    GrunwaldTBoutrosNNPezerNvon OertzenJFernándezGSchallerCet al. Neuronal substrates of sensory gating within the human brain. Biol Psychiatry. (2003) 53:5119. 10.1016/S0006-3223(02)01673-6

  • 178.

    MayerAHanlonFFrancoATeshibaTThomaRClarkVet al. The neural networks underlying auditory sensory gating. Neuroimage. (2009) 44:1829. 10.1016/j.neuroimage.2008.08.025

  • 179.

    KorzyukovOPfliegerMEWagnerMBowyerSMRosburgTSundaresanKet al. Generators of the intracranial P50 response in auditory sensory gating. Neuroimage. (2007) 35:81426. 10.1016/j.neuroimage.2006.12.011

Summary

Keywords

schizophrenia, endophenotypes, intermediate phenotype, prepulse inhibition, P50, sensory gating, sensorimotor gating, startle reflex

Citation

Rovný R, Besterciová D and Riečanský I (2020) Genetic Determinants of Gating Functions: Do We Get Closer to Understanding Schizophrenia Etiopathogenesis?. Front. Psychiatry 11:550225. doi: 10.3389/fpsyt.2020.550225

Received

08 April 2020

Accepted

12 October 2020

Published

25 November 2020

Volume

11 - 2020

Edited by

Xiancang Ma, First Affiliated Hospital of Xi'an Jiaotong University, China

Reviewed by

Boris B. Quednow, University of Zurich, Switzerland; Alex Hatzimanolis, National and Kapodistrian University of Athens, Greece

Updates

Copyright

*Correspondence: Igor Riečanský

This article was submitted to Behavioral and Psychiatric Genetics, a section of the journal Frontiers in Psychiatry

Disclaimer

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

Outline

Figures

Cite article

Copy to clipboard


Export citation file


Share article

Article metrics