Habituation learning: insights from zebrafish larvae

Abstract

Habituation is evolutionary conserved and often considered as one of the simplest forms of learning, however, the underlying mechanisms are highly complex. Extensive research has been conducted over the last few decades to understand the mechanisms of habituation in vertebrate and invertebrate species. Zebrafish (Danio rerio) has emerged as a crucial model for exploring the underlying mechanisms of habituation. Due to the possibility for genetic manipulations and non-invasive visualization of neuronal activity across the entire larval brain and genetically encoded fluorescent sensors allowing the detection of different neurotransmitters linked to behavioral processes, larval zebrafish provides a great vertebrate model to investigate habituation learning. In our review, we summarize recent insights into habituation learning as well as habituation deficits under neuropathological conditions gained from zebrafish larvae.

Introduction

For an animal, enhancing its selective attention to noteworthy environmental features allows the conservation of energy while remaining attentive. This sensory filtering requires rapid processing of incoming information and engages various neural mechanisms (Ramaswami, 2014). Habituation is defined as the ability to filter out irrelevant stimuli from important stimuli by suppressing responses to repetitive non-salient stimuli, resulting in a progressive decline in response frequency and/or magnitude (Rankin et al., 2009). Habituation is the simplest form of non-associative learning and is evolutionarily conserved across vertebrates (Carey et al., 1998; Halberstadt and Geyer, 2009; Wolman et al., 2011). As habituation allows an animal to filter out irrelevant stimuli from important stimuli, habituation learning is believed to be a prerequisite for more complex types of learning (Rankin et al., 2009).

Learning is the biological process of acquiring new knowledge, and memory is the process of reconstructing this acquired knowledge over time (Kandel et al., 2014). Non-associative learning refers to the process in which an animal's response changes toward a stimulus in absence of any association with other stimuli that would induce such change. The two major form of non-associative learning are habituation and sensitization (Ioannou and Anastassiou-Hadjicharalambous, 2021). Over the last few decades, extensive research has been conducted to understand the mechanisms of habituation in vertebrates and invertebrates (Thompson, 2009). The description of the gill-withdrawal reflex in Aplysia by Pinsker et al. represented a major step in neuroscience (Pinsker et al., 1970). Owing to the relative simplicity of the nervous system and accessibility to intracellular electrophysiological recordings of Aplysia, it was possible to dissect the cellular mechanisms that alter synaptic properties within this circuit and habituate the withdrawal reflex (Castellucci and Kandel, 1974). These studies revealed that habituation results from excitatory synaptic transmission (Castellucci and Kandel, 1974; Cohen et al., 1997). However, although habituation learning has been well studied at the behavioral level only little is known about the neuronal mechanisms underlying habituation.

In larval zebrafish (Danio rerio), repetitive presentation of visual, acoustic, or tactile stimuli can induce the formation of habituation memory (Wolman et al., 2011; Burgess and Granato, 2007a; Randlett et al., 2019). An acoustic stimulus triggers a rapid escape maneuver of the larvae, termed the C-bend, which is initiated by the Mauthner cells (M-cells) located in the hindbrain (Burgess and Granato, 2007b; Korn and Faber, 2005). In response to a sudden decrease in illumination, the so-called dark-flash, zebrafish larvae respond with an escape maneuver characterized by an O-bend of their body (Burgess and Granato, 2007a), which is not mediated by the M-cells (Wolman et al., 2011; Burgess and Granato, 2007b). The neuronal pathways and molecular mechanisms that induce these defensive escape responses and which have been extensively investigated in zebrafish larvae are reviewed elsewhere (Corradi and Filosa, 2021; Hamling and Schoppik, 2018; Hale et al., 2016; Wolman and Granato, 2012; Portugues and Engert, 2009; Korn and Faber, 2005; Faber et al., 1991; Eaton et al., 1991).

Habituation can be quantified as a decrease in the magnitude of the startle response or as a binary reduction in the probability of executing a startle response (Rankin et al., 2009). Several parameters, such as stimulus intensity, frequency, and number of stimuli, determine the strength and speed of habituation (Rankin et al., 2009; Thompson and Spencer, 1966). Like other forms of plasticity, habituation exists in at least two mechanistically distinct forms: transient short-term habituation and protein synthesis-dependent long-term habituation (Rankin et al., 2009; Wolman et al., 2011). Both escape behaviors, the C-bend and the O-bend in response to acoustic stimuli or dark-flash stimuli, respectively, exhibit short-term and long-term habituation (Roberts et al., 2011; Wolman et al., 2011; Roberts et al., 2016).

Here, we review the aspects of investigating habituation learning in zebrafish larvae at the molecular, circuit, and behavioral level to gain an understanding of the underlying mechanisms that drive habituation toward different stimuli (see Table 1). Furthermore, we summarize recent insights gained from studying habituation deficits in neuropathological conditions.

Molecular mechanisms of habituation

Over the past decade, significant progress has been made toward understanding the mechanisms of habituation learning in C. elegans and Drosophila at the molecular level, including different key regulators, their course of action and degree of interaction (Crawley et al., 2017; Ardiel et al., 2016; Eddison et al., 2012; Wolf et al., 2007; Rankin and Wicks, 2000). Given the increased complexity of the vertebrate nervous system, it remains still largely open whether additional molecular regulators exist in comparison to invertebrates that drive habituation in vertebrates.

By utilizing a genome-wide approach, several genes have been identified that are linked to habituation deficits in zebrafish, including the pregnancy associated plasma protein-aa (pappaa), pyruvate carboxylase a (pcxa) (Wolman et al., 2015), huntingtin interacting protein 14 (hip14), potassium voltage-gated channel member 1a (kcna1a) which encodes the shaker-like voltage-gated K+ channel subunit Kv1.1 (Nelson et al., 2020), the calcium voltage-gated channel auxiliary subunit alpha-2/delta-3 (cacna2d3) (Santistevan et al., 2022) and ap2s1 which encodes Adapter Protein 2 subunit σ (AP2σ) (Zúñiga Mouret et al., 2024). These genome-wide approach present a step toward describing the molecular players involved in habituation in the vertebrate system.

pappaa is expressed in the M-cells and several clusters of neighboring hindbrain interneurons known to modulate M-cell activation (Wolman et al., 2015) and encodes an extracellular metalloprotease known to increase insulin-like growth factor (IGF) bioavailability to bind to its receptor by cleaving insulin-like growth factor binding protein (Conover et al., 2004). pappaa mutant larvae display habituation deficits toward acoustic stimuli. Pharmacological activation of the two IGF1R signaling downstream effectors PI3-kinase (PI3K) or Akt, respectively, improves acoustic startle response habituation in pappaa mutant larvae. Accordingly, PAPP-A regulates acoustic startle response habituation through IGF signaling and its metalloprotease activity is required for this (Wolman et al., 2015). Deploying nf1 mutant larvae to investigate pathways that control neurofibromin-dependent habituation Wolman et al. found that nf1 mutant larvae exhibit reduced long-term habituation of the dark-flash response. Inhibition of the Ras effectors MAPK and PI3K improved long-term habituation in nf1 mutant supporting that neurofibromin acts through the Ras/MAPK/PI3K signaling pathway to regulate long-term memory. Besides affecting long-term habituation toward dark-flash stimuli, nf1 deficiency also reduces short-term habituation toward acoustic and dark-flash stimuli. Enhancing cAMP signaling has been shown to be sufficient to improve short-term habituation of the dark-flash response in nf1 mutant larvae suggesting that cAMP signaling regulates habituation in a NF1-dependent manner (Wolman et al., 2014). The palmitoyltransferase Hip14 regulates synaptic depression of the M-cell lateral dendrites during acoustic startle response habituation and regulates habituation learning through the voltage-gated K+ channel subunit Kv1.1. Localization of Kv1.1 to presynaptic terminals of the M-cell is mediated through palmitoyltransferase activity of Hip14. Furthermore, pharmacological manipulations of Ras/MAPK/PI3K and cAMP signaling, respectively, suggests that Hip14 acts independent of PAPP-AA/IGF1R and NF1 habituation learning pathways (Nelson et al., 2020).

Different subunits of the AP2 complex modulate acoustic startle response habituation in a similar manner, suggesting that the AP2 acts as a heterotetramer, and subunits do not perform functions linked to acoustic startle response habituation independently. Disrupting ap2s1, which encodes subunit σ (AP2σ), results in deficient acoustic startle response habituation, while habituation toward dark-flash stimuli is enhanced. Thus, ap2s1 modulates habituation in a sensory modality-specific manner. Because neuronal expression of ap2s1 after embryonal stages is sufficient to rescue habituation deficits in ap2s1 mutants, the AP2 complex seems dispensable for developmental wiring of circuits involved in acoustic habituation learning but rather targets membrane-associated proteins for endocytosis after developmental stages and thereby regulates habituation learning (Zúñiga Mouret et al., 2024). Furthermore, kinesin family member 2a (kif2a), regulating microtubule depolymerization via an ATP-driven process (Manning et al., 2007), has been shown to affect long-term habituation toward dark-flash stimuli. However, increased apoptosis and deficient neuronal cell proliferation displayed in kif2a mutant larvae may have contributed to deficits in long-term habituation (Partoens et al., 2021).

While most of the identified mechanisms of habituation act within brain circuits, non-autonomous regulators have been largely unexplored. More recently, Cadherin-16 (Cdh16) has been described to function via an endocrine organ to regulate calcium homeostasis and ultimately regulate sensory gating through habituation (Schloss et al., 2025). Cdh16 regulates whole-body calcium by suppressing the expression of the hormone Stanniocalcin 1l (stc1l). Stc1l limits proliferation of a specific class of ionocytes, specialized to promote calcium uptake from the environment, through suppression of Papp-aa (Hwang, 2009; Li et al., 2021). In absence of Cdh16, calcium uptake is severely limited and acoustic startle threshold is lowered resulting in deficient acoustic startle response habituation of the larvae. Interestingly, habituation toward dark-flash stimuli is not affected, indicating that Cdh16 regulates habituation learning through calcium homeostasis in a sensory-specific manner. Similar as for AP2σ (Zúñiga Mouret et al., 2024), Cdh16 seems to regulate habituation learning after establishment of the acoustic startle circuit (Schloss et al., 2025).

Deficits in acoustic startle response habituation frequently co-segregate with a lowered acoustic startle threshold, as in the case of cacna2d3 (Santistevan et al., 2022), pappaa (Wolman et al., 2015) or cdh16 mutant larvae (Schloss et al., 2025). However, in pcxa mutant larvae reduced acoustic startle response habituation occurred independently of acoustic sensitivity (Wolman et al., 2015) and vice versa, other mutations caused acoustic hypersensitivity of the larvae without affecting acoustic startle response habituation (Marsden et al., 2018). Thus, genetic pathways that control these two behaviors seem to partially overlap, and are to some extent controlled by independent molecular pathways.

Neuronal circuits involved in habituation

Both, short- and long-term habituation of the acoustic startle response are N-methyl-D-aspartate-receptor (NMDA-R)-depended (Roberts et al., 2011; Marsden and Granato, 2015; Roberts et al., 2016). Additionally, short-term habituation of the acoustic startle response also depends on the glycine receptor (Marsden and Granato, 2015).

The M-cell receives inputs at different sites which converge and can give rise to different behavioral outputs (Hale et al., 2016). At the axon initial segment of the M-cell glutamate release is dependent on NMDA-R activity and this glutamate release displays a NMDA-R-dependent depression. Whereas at the lateral dendrite glutamate release is not regulated by NMDA-R but instead shows a frequency-dependent depression (Bátora et al., 2021). Further, activity of the M-cell lateral dendrite determines acoustic startle probability (Marsden and Granato, 2015). Together this suggests that the axon initial segment of the M-cell might be responsible for inducing depression of synaptic activity during short-term acoustic startle response habituation, and the lateral dendrite of the M-cell serves as a baseline component for the startle threshold. While a set of spinal inhibitory neurons, CoLos, have been ruled out as a source for downstream inhibition of the M-cell during acoustic startle response habituation (Marsden and Granato, 2015), a feed-forward interneuron population has been noticed which affects habituation by modulating the axon initial segment of the M-cell (Bátora et al., 2021).

During habituation of the acoustic startle response the activity of dorsal raphe nucleus serotonergic neurons, which project their axons near the M-cell dendrites, decreases, and the amount of this decrease is proportional to behavioral habituation. Short-term habituation of the acoustic startle response differs between individual larvae; these differences are stable over developmental days and heritable. Reducing serotonin content in dorsal raphe nucleus neurons increases habituation, whereas serotonergic agonism or dorsal raphe nucleus activation reduces habituation, suggesting that inter-individual differences in serotonergic signaling in the M-cell circuit affect behavioral output (Pantoja et al., 2016). Individuals who habituated quickly to acoustic stimuli displayed increased spontaneous activity in dopaminergic caudal hypothalamic neurons. Thus, serotonin operates contrary to dopamine in regulating habituation to acoustic stimuli. Furthermore, Pantoja et al. showed that inter-individual differences in acoustic startle response habituation affect whole-brain activity patterns. Individuals with slow habituation rates displayed increased activity in the absence of any stimuli in brain regions (such as the habenula, interpeduncular nucleus, and pallium), which were activated by acoustic stimuli in fast habituating individuals (Pantoja et al., 2020).

Also, for long-term habituation of the dark-flash response several relevant pathways have been identified, including melatonin, estrogen, and GABAergic signaling. Partial antagonism of GABA_A and/or GABA_C receptors strongly suppresses dark-flash response habituation, highlighting an important role of GABAergic signaling for habituation learning. Using Ca²⁺ imaging while presenting repeated dark-flash to the larvae they further identified GABAergic neurons characterized by a short burst of activity to the stimulus onset (Lamiré et al., 2023). The involvement of GABAergic signaling suggests a model in which the potentiation of inhibition suppresses sensory-induced motor output during habituation (Ramaswami, 2014). In contrast to GABAergic signaling, melatonin and estrogen promote behavioral habituation toward dark-flash stimuli. Melatonin primarily affects habituation of the response probability by inducing a more rapid decay, while it does not strongly alter habituation of the displacement of the larvae after executing a O-bend. This suggests that melatonin modulates specific behavioral aspects during long-term habituation (Lamiré et al., 2023). Ethinyl estradiol, an estrogen receptor agonist, also promotes long-term habituation toward dark-flash stimuli, however, acoustic startle response habituation is unaffected (Lamiré et al., 2023; Hsiao et al., 2025). Moreover, estradiol does not mediate its promoting effects on dark-flash habituation through the two main classes of estrogen receptors. Notably, esr1, esr2a, and gper1 mutants, deficient for one of the estrogen receptors, displayed increased habituation, indicating that estrogen receptors inhibit long-term habituation. Accordingly, it is less evident so far how specific estrogen signaling modulates long-term habituation toward dark-flash stimuli (Hsiao et al., 2025).

Thus, several regulators and neurotransmitters have been identified as contributing to habituation. To shed light on whether these molecular pathways and neurotransmitter systems act independently or interact with each other, as well as whether they act through overlapping neuronal circuits, Nelson et al. combined pharmacogenetic pathway analysis with whole-brain activity mapping and monitored acoustic startle response habituation.

Antagonizing the NMDA or dopamine receptor reduced habituation to acoustic stimuli in wild-type larvae, whereas the same treatment in hip14 mutant animals did not further reduce habituation. Furthermore, hip14 mutant animals and treatment with NMDA or dopamine receptor inhibitors displayed similar whole-brain activity patterns. Therefore, they suggested that Hip14 acts in a common pathway with the NMDA-R and the dopamine receptor to promote acoustic startle response habituation. In contrast, glycine-receptor inhibitor reduced habituation in both hip14 mutant and wildtype animals, suggesting that Hip14 and glycine have independent roles in regulating acoustic startle response habituation. Finally, while in wildtype larvae, dopamine receptor inhibition impaired habituation, the same treatment restored habituation in ap2s1 mutants. Papp-aa promotes habituation independent of NMDA and glycine receptor signaling but seems to be required to suppress dopamine signaling during habituation learning. Accordingly, Hip14 cooperates with dopamine and NMDA-R signaling to foster habituation, whereas Ap2s1 and Papp-aa fosters habituation by antagonizing dopamine signaling, proposing two opposing roles for dopaminergic neuromodulation. Additionally, in ap2s1 and pappaa mutant larvae neuronal activity following presentation of repetitive acoustic stimuli was increased in regions labeling dopaminergic neurons, suggesting that Ap2s1 and Papp-aa regulate habituation by limiting endogenous dopamine signaling through modulation of activity of dopaminergic neurons.

Using the same pharmacogenetic pathway analysis, they found that cacna2d3 and Kv1.1, respectively, act independent of NMDA, dopamine, and glycine receptor signaling to regulate habituation learning. Interestingly, in hip14 mutants, changes in neuronal activity upon repetitive habituating acoustic stimuli occurred in several regions of the larvae brain, while in kcna1a mutant brains these changes were more restricted to a set of hindbrain neurons. Together with the fact that hip14 mutants displayed more severe acoustic startle response habituation deficits than kcna1a mutants, supports the idea that Hip14 targets additional substrates beside Kv1.1 to modulate acoustic startle response habituation (Nelson et al., 2020, 2023). By grouping eight molecular regulators of habituation into five distinct pathways, termed modules, they found that three of the modules were functionally interconnected: module 1 (consisting of Hip14, as well as NMDA and dopamine receptor signaling), module 2 (consisting of Hip14 and Kv1.1), and module 3 (consisting of Papp-aa and Ap2s1). Module 4 (defined by Glycine signaling) and module 5 (defined by cacna2d3) seem to be functionally independent from each other and all other three modules, proposing that some habituation regulating pathways act in parallel (Nelson et al., 2023).

By examining neuronal activity while presenting repeated dark-flash to the larva, Lamiré et al. further identified functional groups of neurons that differed based on their rate of adaptation, stimulus response shape, and anatomical locations. Most groups of neurons attenuated their responses to repeated stimuli; however, they identified populations of neurons that did not adapt their responses to repeated stimuli. These non-adapting were distributed across brain areas, suggesting a distributed habituation learning process (Lamiré et al., 2023). Such a model of a distributed habituation learning process, in which non-habituated signals are transmitted throughout the brain, is further supported with brain-wide imaging data where distributed neurons displayed differential rates of habituation toward looming stimuli (Marquez-Legorreta et al., 2022). Marquez-Legorreta et al. showed that distinct functional categories of loom-sensitive neurons are located at characteristic locations throughout the brain. Using graph theory, they identified a visual circuit that habituates minimally toward loom stimuli, a moderately habituating population of neurons throughout the midbrain suggested to mediate the sensorimotor transformation, and a population of neurons in premotor regions located in the hindbrain and higher-order forebrain regions that represent threats (Marquez-Legorreta et al., 2022). To further investigate the neuronal substrates of the dark-looming stimulus, Fotowat and Engert performed calcium imaging in larvae in response to visual stimulation and constructed a circuit model of visually evoked escape behavior, suggesting the presence of two separate pathways. One relays visual information to the escape network in the brain stem to generate escape maneuvers, while the second one emerges to inhibit these escape responses. The second pathway is under contextual modulation, which is responsible for progressively suppressing escapes (Fotowat and Engert, 2023).

Behavioral decomposition of habituation

Through behavioral analysis, Randlett et al. showed that habituation of the response to repetitive dark-flash stimuli involves the adjustment of multiple behavioral parameters, including the latency of the response, movement duration, and maximal bend amplitude. These different behavioral components adapt with different habituation kinetics and habituate independently of each other. They found that habituation of a few components involves dopaminergic or serotonergic signaling, some require Nf1, while others do not, and only one of the behavioral components is modulated by the circadian rhythm. Thus, habituation of different behavioral response components occurs through separate molecular mechanisms, and the modularity of behavioral habituation is based on the context of the animal. This points toward a modular model in which visual habituation emerges from multiple independent processes, each of which controls the adaptation of specific behavioral components (Randlett et al., 2019). Since most studies quantify habituation as a decrease in the magnitude of the startle response or as a binary reduction in the probability of executing a startle response, these findings highlight a relatively unexplored aspect of behavioral habituation.

Growing evidence points toward a phenotypic plasticity in learning among vertebrates (Miner et al., 2005). Larvae exposed to an enriched environment after hatching display enhanced short-term habituation learning toward acoustic stimuli at juvenile stages (Gatto et al., 2024). Further highlighting that inter-individual behavioral variability may emerge due to genetic (Pantoja et al., 2016, 2020) and environmental components (Gatto et al., 2024).

Habituation impairment in neurological disease

Impairments in sensory filtering are common in many neurological disorders, and deficiencies in habituation have been associated with several neurodevelopmental and neurodegenerative diseases and traumatic brain injuries (Perry et al., 2007; Chen et al., 2016; Papesh et al., 2019). Mutations in several genes encoding key regulators of habituation identified in zebrafish larvae are also associated with cognitive deficits and learning disabilities in humans (Wolman et al., 2014, 2015; Nelson et al., 2020; Santistevan et al., 2022; Zúñiga Mouret et al., 2024).

Mutations in AP2S1 alleles have been associated with ASD and ADHD in humans and may result in learning disabilities and cognitive deficits. Disrupting ap2s1 in zebrafish larvae results in severe acoustic startle response habituation deficits, replicating some of the behavioral phenotypes in humans with ASD, such as increased sensitivity and reduced habituation of behavioral responses to acoustic stimuli (Zúñiga Mouret et al., 2024; Satterstrom et al., 2020; Hannan et al., 2015).

Nonsense mutation in the highly conserved fmr1 gene, the silencing of which causes Fragile X syndrome (FXS) in humans, leads to decreased habituation toward visual stimuli in larvae, replicating a behavioral phenotype in human patients with FXS (Marquez-Legorreta et al., 2022; Constantin et al., 2020; Ethridge et al., 2016). Moreover, fmr1 mutant larvae showed increased network correlations together with greater transmission from sensory to premotor regions, which suggests a mechanism for slower sensorimotor learning in patients with FXS (Marquez-Legorreta et al., 2022).

Neurofibromatosis type 1 (NF1) is associated, in addition to a broad range of clinical characteristics, with learning disabilities, cognitive deficits, and attention deficits (Cichowski and Jacks, 2001; Hyman et al., 2006). Larvae deficient for nf1 display short- and long-term habituation learning deficits with characteristics reminiscent in human NF1 patients. Furthermore, habituation deficits caused by genetic loss of nf1 in zebrafish larvae are reversible by targeting NF1 downstream signaling pathways supporting the investigation of therapeutical targets in the treatment of behavioral dysfunction in NF1 patients (Wolman et al., 2014).

Further, zebrafish larvae have been also used to study mutations reported in lissencephaly, microcephaly, and drug-resistant epilepsy by looking at habituation learning (Partoens et al., 2021). More recently it has been shown that habituation of the acoustic startle response in larval zebrafish is impaired after a concussive impact, and that the severity of the concussive impact affects the habituation performance of the larvae (Beppi et al., 2022; Köcher et al., 2024).

Conclusions

Although habituation is often considered one of the simplest forms of learning, its underlying mechanisms are complex. Multiple molecular regulators are involved in converging or separating neuronal pathways in different parts of the nervous system and are activated by different types of stimuli. It remains largely undetermined whether the pathways explored so far act through overlapping neuronal circuits.

A challenge in neuroscience is to address the link between brain activity and specific behaviors. Larval zebrafish (Danio rerio) provide a great vertebrate model to address this aspect due to the possibility for high-throughput behavioral measurements, genetic manipulations (Orger and de Polavieja, 2017) and non-invasive visualization of neuronal activity across the entire larval brain at micrometer resolution, which remains unfeasible in other vertebrate species (Ahrens et al., 2013; Migault et al., 2018). Moreover, genetically encoded fluorescent sensors allow the detection of different neurotransmitters linked to behavioral processes (Sun et al., 2018; Day-Cooney et al., 2023).

It would be interesting to gain a more comprehensive understanding of the network process during habituation learning by determining neurotransmitter subtypes and assessing synaptic relationships between neurons. Performing calcium imaging concurrent with co-labeling neurons with transgenic markers for neurotransmitter subtypes, as well as optogenetic manipulation at specific parts of the circuit, may provide greater insight into these network processes during habituation. Behavioral analysis combined with calcium imaging approaches may also provide more in-depth insights into the brain activity underlying changes in response strategies. Behavioral sequences can often be constructed using simple rules that connect sensory input with motor output, also referred to as behavioral algorithms (Marques et al., 2018; Johnson et al., 2020). Thus, modeling techniques may help uncover the basic control principles underlying behavior and provide further insight into the basic building blocks of habituation learning toward different sensory stimuli.

Additionally, it would be interesting to examine further genes associated with neurodevelopmental diseases in zebrafish larvae to obtain a better understanding of the genetic complexity and phenotypic diversity of these diseases in the future. Investigating the underlying genetic and cellular mechanisms that regulate habituation learning may provide insights into the identification of potential therapeutic targets.

References

• 1

  Ahrens M. B. Orger M. B. Robson D. N. Li J. M. Keller P. J. (2013). Whole-brain functional imaging at cellular resolution using light-sheet microscopy. Nat. Methods10, 413–420. doi: 10.1038/nmeth.2434

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 2

  Ardiel E. L. Giles A. C. Yu A. J. Lindsay T. H. Lockery S. R. Rankin C. H. et al . (2016). Dopamine receptor DOP-4 modulates habituation to repetitive photoactivation of a C. elegans polymodal nociceptor. Learn Mem. 23, 495–503. doi: 10.1101/lm.041830.116

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 3

  Bátora D. Zsigmond Á. Lorincz I. Z. Szegvári G. Varga M. Málnási-Csizmadia A. et al . (2021). Subcellular dissection of a simple neural circuit: functional domains of the mauthner-cell during habituation. Front. Neural. Circuits15:648487. doi: 10.3389/fncir.2021.648487

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 4

  Beppi C. Penner M. Straumann D. Bögli S. Y. (2022). A non-invasive biomechanical model of mild TBI in larval zebrafish. PLoS ONE17:e0268901. doi: 10.1371/journal.pone.0268901

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 5

  Burgess H. A. Granato M. (2007a). Modulation of locomotor activity in larval zebrafish during light adaptation. J. Exp. Biol.210, 2526–2539. doi: 10.1242/jeb.003939

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 6

  Burgess H. A. Granato M. (2007b). Sensorimotor gating in larval zebrafish. J. Neurosci. 27, 4984–4994. doi: 10.1523/JNEUROSCI.0615-07.2007

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 7

  Carey R. J. Dai H. Gui J. (1998). Effects of dizocilpine (MK-801) on motor activity and memory. Psychopharmacology137, 241–246. doi: 10.1007/s002130050616

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 8

  Castellucci V. F. Kandel E. R. (1974). A quantal analysis of the synaptic depression underlying habituation of the gill-withdrawal reflex in Aplysia. Proc. Natl. Acad. Sci. U S A. 71, 5004–5008. doi: 10.1073/pnas.71.12.5004

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 9

  Chen K. H. Okerstrom K. L. Kingyon J. R. Anderson S. W. Cavanagh J. F. Narayanan N. S. et al . (2016). Startle habituation and midfrontal theta activity in Parkinson disease. J. Cogn. Neurosci. 28, 1923–1932. doi: 10.1162/jocn_a_01012

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 10

  Cichowski K. Jacks T. (2001). NF1 tumor suppressor gene function: narrowing the GAP. Cell104, 593–604. doi: 10.1016/S0092-8674(01)00245-8

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 11

  Cohen T. E. Kaplan S. W. Kandel E. R. Hawkins R. D. (1997). A simplified preparation for relating cellular events to behavior: mechanisms contributing to habituation, dishabituation, and sensitization of the Aplysia gill-withdrawal reflex. J. Neurosci.17, 2886–2899. doi: 10.1523/JNEUROSCI.17-08-02886.1997

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 12

  Conover C. A. Bale L. K. Overgaard M. T. Johnstone E. W. Laursen U. H. Füchtbauer E. M. et al . (2004). Metalloproteinase pregnancy-associated plasma protein A is a critical growth regulatory factor during fetal development. Development131, 1187–1194. doi: 10.1242/dev.00997

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 13

  Constantin L. Poulsen R. E. Scholz L. A. Favre-Bulle I. A. Taylor M. A. Sun B. et al . (2020). Altered brain-wide auditory networks in a zebrafish model of fragile X syndrome. BMC Biol.18:125. doi: 10.1186/s12915-020-00857-6

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 14

  Corradi L. Filosa A. (2021). Neuromodulation and behavioral flexibility in larval zebrafish: from neurotransmitters to circuits. Front. Mol. Neurosci.14:718951. doi: 10.3389/fnmol.2021.718951

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 15

  Crawley O. Giles A. C. Desbois M. Kashyap S. Birnbaum R. Grill B. et al . (2017). A MIG-15/JNK-1 MAP kinase cascade opposes RPM-1 signaling in synapse formation and learning. PLoS Genet.13:e1007095. doi: 10.1371/journal.pgen.1007095

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 16

  Day-Cooney J. Dalangin R. Zhong H. Mao T. (2023). Genetically encoded fluorescent sensors for imaging neuronal dynamics in vivo. J. Neurochem.164, 284–308. doi: 10.1111/jnc.15608

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 17

  Eaton R. C. DiDomenico R. Nissanov J. (1991). Role of the Mauthner cell in sensorimotor integration by the brain stem escape network. Brain Behav. Evol.37, 272–285. doi: 10.1159/000114365

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 18

  Eddison M. Belay A. T. Sokolowski M. B. Heberlein U. (2012). A genetic screen for olfactory habituation mutations in Drosophila: analysis of novel foraging alleles and an underlying neural circuit. PLoS ONE7:e51684. doi: 10.1371/journal.pone.0051684

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 19

  Ethridge L. E. White S. P. Mosconi M. W. Wang J. Byerly M. J. Sweeney J. A. et al . (2016). Reduced habituation of auditory evoked potentials indicate cortical hyper-excitability in Fragile X Syndrome. Transl. Psychiatry6:e787. doi: 10.1038/tp.2016.48

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 20

  Faber D. S. Korn H. Lin J. W. (1991). Role of medullary networks and postsynaptic membrane properties in regulating Mauthner cell responsiveness to sensory excitation. Brain Behav. Evol.37, 286–297. doi: 10.1159/000114366

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 21

  Fotowat H. Engert F. (2023). Neural circuits underlying habituation of visually evoked escape behaviors in larval zebrafish. Elife12:e82916. doi: 10.7554/eLife.82916

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 22

  Gatto E. Lucon-Xiccato T. Bertolucci C. (2024). Environmental conditions shape learning in larval zebrafish. Behav. Processes218:105045. doi: 10.1016/j.beproc.2024.105045

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 23

  Halberstadt A. L. Geyer M. A. (2009). Habituation and sensitization of acoustic startle: opposite influences of dopamine D1 and D2-family receptors. Neurobiol. Learn. Mem. 92, 243–248. doi: 10.1016/j.nlm.2008.05.015

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 24

  Hale M. E. Katz H. R. Peek M. Y. Fremont R. T. (2016). Neural circuits that drive startle behavior, with a focus on the Mauthner cells and spiral fiber neurons of fishes. J. Neurogenet.30, 89–100. doi: 10.1080/01677063.2016.1182526

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 25

  Hamling K. R. Schoppik D. (2018). Sensory gating: cellular substrates of surprise. Curr. Biol.28, R871–R873. doi: 10.1016/j.cub.2018.06.023

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 26

  Hannan F. M. Howles S. A. Rogers A. Cranston T. Gorvin C. M. Babinsky V. N. et al . (2015). Adaptor protein-2 sigma subunit mutations causing familial hypocalciuric hypercalcaemia type 3 (FHH3) demonstrate genotype-phenotype correlations, codon bias and dominant-negative effects. Hum. Mol. Genet. 24, 5079–50792. doi: 10.1093/hmg/ddv226

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 27

  Hsiao A. Darvaux-Hubert I. Hicks D. Joux E. De Freitas S. Dracos E. et al . (2025). Estradiol promotes habituation learning via an unidentified target, bypassing the suppressive effects of established ERs. Endocrinology166:bqaf110. doi: 10.1210/endocr/bqaf110

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 28

  Hwang P. P. (2009). Ion uptake and acid secretion in zebrafish (Danio rerio). J. Exp. Biol.212(Pt 11), 1745–1752. doi: 10.1242/jeb.026054

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 29

  Hyman S. L. Arthur Shores E. North K. N. (2006). Learning disabilities in children with neurofibromatosis type 1: subtypes, cognitive profile, and attention-deficit-hyperactivity disorder. Dev. Med. Child. Neurol. 48, 973–977. doi: 10.1111/j.1469-8749.2006.tb01268.x

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 30

  Ioannou A. Anastassiou-Hadjicharalambous X. (2021). Non-associative learning. Encycl. Evol. Psychol. Sci. 5419–5432. doi: 10.1007/978-3-319-19650-3_1027

  • CrossRef
  • Google Scholar

• 31

  Johnson R. E. Linderman S. Panier T. Wee C. L. Song E. Herrera K. J. et al . (2020). Probabilistic models of larval zebrafish behavior reveal structure on many scales. Curr. Biol.30, 70–82.e4. doi: 10.1016/j.cub.2019.11.026

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 32

  Kandel E. R. Dudai Y. Mayford M. R. (2014). The molecular and systems biology of memory. Cell157, 163–186. doi: 10.1016/j.cell.2014.03.001

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 33

  Köcher L. Beppi C. Penner M. Meyer S. Bögli S. Y. Straumann D. et al . (2024). Concussion leads to opposing sensorimotor effects of habituation deficit and fatigue in zebrafish larvae. Brain Commun.6:fcae407. doi: 10.1093/braincomms/fcae407

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 34

  Korn H. Faber D. S. (2005). The Mauthner cell half a century later: a neurobiological model for decision-making?Neuron47, 13–28. doi: 10.1016/j.neuron.2005.05.019

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 35

  Lamiré L. A. Haesemeyer M. Engert F. Granato M. Randlett O. (2023). Functional and pharmacological analyses of visual habituation learning in larval zebrafish. Elife12:RP84926. doi: 10.7554/eLife.84926

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 36

  Li S. Liu C. Goldstein A. Xin Y. Ke C. Duan C. et al . (2021). Calcium state-dependent regulation of epithelial cell quiescence by stanniocalcin 1a. Front. Cell Dev. Biol. 9:662915. doi: 10.3389/fcell.2021.662915

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 37

  Manning A. L. Ganem N. J. Bakhoum S. F. Wagenbach M. Wordeman L. Compton D. A. et al . (2007). The kinesin-13 proteins Kif2a, Kif2b, and Kif2c/MCAK have distinct roles during mitosis in human cells. Mol. Biol. Cell18, 2970–2979. doi: 10.1091/mbc.e07-02-0110

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 38

  Marques J. C. Lackner S. Félix R. Orger M. B. (2018). Structure of the zebrafish locomotor repertoire revealed with unsupervised behavioral clustering. Curr. Biol.28, 181–195.e5. doi: 10.1016/j.cub.2017.12.002

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 39

  Marquez-Legorreta E. Constantin L. Piber M. Favre-Bulle I. A. Taylor M. A. Blevins A. S. et al . (2022). Brain-wide visual habituation networks in wild type and fmr1 zebrafish. Nat. Commun. 13:895. doi: 10.1038/s41467-022-28299-4

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 40

  Marsden K. C. Granato M. (2015). In vivo Ca(2+) imaging reveals that decreased dendritic excitability drives startle habituation. Cell Rep.13, 1733–1740. doi: 10.1016/j.celrep.2015.10.060

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 41

  Marsden K. C. Jain R. A. Wolman M. A. Echeverry F. A. Nelson J. C. Hayer K. E. et al . (2018). A Cyfip2-dependent excitatory interneuron pathway establishes the innate startle threshold. Cell Rep.23, 878–887. doi: 10.1016/j.celrep.2018.03.095

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 42

  Migault G. van der Plas T. L. Trentesaux H. Panier T. Candelier R. Proville R. et al . (2018). Whole-brain calcium imaging during physiological vestibular stimulation in larval zebrafish. Curr. Biol.28, 3723–3735.e6. doi: 10.1016/j.cub.2018.10.017

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 43

  Miner B. G. Sultan S. E. Morgan S. G. Padilla D. K. Relyea R. A. (2005). Ecological consequences of phenotypic plasticity. Trends Ecol. Evol.20, 685–692. doi: 10.1016/j.tree.2005.08.002

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 44

  Nelson J. C. Shoenhard H. Granato M. (2023). Integration of cooperative and opposing molecular programs drives learning-associated behavioral plasticity. PLoS Genet.19:e1010650. doi: 10.1371/journal.pgen.1010650

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 45

  Nelson J. C. Witze E. Ma Z. Ciocco F. Frerotte A. Randlett O. et al . (2020). Acute regulation of habituation learning via posttranslational palmitoylation. Curr. Biol.30, 2729–2738.e4. doi: 10.1016/j.cub.2020.05.016

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 46

  Orger M. B. de Polavieja G.G. (2017). Zebrafish behavior: opportunities and challenges. Annu. Rev. Neurosci. 40, 125–147. doi: 10.1146/annurev-neuro-071714-033857

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 47

  Pantoja C. Hoagland A. Carroll E. C. Karalis V. Conner A. Isacoff E. Y. et al . (2016). Neuromodulatory regulation of behavioral individuality in zebrafish. Neuron. 91, 587–601. doi: 10.1016/j.neuron.2016.06.016

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 48

  Pantoja C. Larsch J. Laurell E. Marquart G. Kunst M. Baier H. et al . (2020). Rapid effects of selection on brain-wide activity and behavior. Curr. Biol.30, 3647–3656.e3. doi: 10.1016/j.cub.2020.06.086

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 49

  Papesh M. A. Elliott J. E. Callahan M. L. Storzbach D. Lim M. M. Gallun F. J. et al . (2019). Blast exposure impairs sensory gating: evidence from measures of acoustic startle and auditory event-related potentials. J. Neurotrauma36, 702–712. doi: 10.1089/neu.2018.5801

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 50

  Partoens M. De Meulemeester A. S. Giong H. K. Pham D. H. Lee J. S. de Witte P. A. et al . (2021). Modeling neurodevelopmental disorders and epilepsy caused by loss of function of kif2a in Zebrafish. eNeuro 8. doi: 10.1523/ENEURO.0055-21.2021

  • CrossRef
  • Google Scholar

• 51

  Perry W. Minassian A. Lopez B. Maron L. Lincoln A. (2007). Sensorimotor gating deficits in adults with autism. Biol. Psychiatry61, 482–486. doi: 10.1016/j.biopsych.2005.09.025

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 52

  Pinsker H. Kupfermann I. Castellucci V. Kandel E. (1970). Habituation and dishabituation of the gill-withdrawal reflex in Aplysia. Science167, 1740–1742. doi: 10.1126/science.167.3926.1740

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 53

  Portugues R. Engert F. (2009). The neural basis of visual behaviors in the larval zebrafish. Curr. Opin. Neurobiol.19, 644–647. doi: 10.1016/j.conb.2009.10.007

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 54

  Ramaswami M. (2014). Network plasticity in adaptive filtering and behavioral habituation. Neuron82, 1216–1229. doi: 10.1016/j.neuron.2014.04.035

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 55

  Randlett O. Haesemeyer M. Forkin G. Shoenhard H. Schier A. F. Engert F. et al . (2019). Distributed plasticity drives visual habituation learning in larval zebrafish. Curr. Biol. 29, 1337–1345.e4. doi: 10.1016/j.cub.2019.02.039

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 56

  Rankin C. H. Abrams T. Barry R. J. Bhatnagar S. Clayton D. F. Colombo J. et al . (2009). Habituation revisited: an updated and revised description of the behavioral characteristics of habituation. Neurobiol. Learn. Mem. 92, 135–138. doi: 10.1016/j.nlm.2008.09.012

  • CrossRef
  • Google Scholar

• 57

  Rankin C. H. Wicks S. R. (2000). Mutations of the Caenorhabditis elegans brain-specific inorganic phosphate transporter eat-4 affect habituation of the tap-withdrawal response without affecting the response itself. J. Neurosci.20, 4337–4344. doi: 10.1523/JNEUROSCI.20-11-04337.2000

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 58

  Roberts A. C. Pearce K. C. Choe R. C. Alzagatiti J. B. Yeung A. K. Bill B. R. et al . (2016). Long-term habituation of the C-start escape response in zebrafish larvae. Neurobiol Learn Mem.134(Pt B), 360–368. doi: 10.1016/j.nlm.2016.08.014

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 59

  Roberts A. C. Reichl J. Song M. Y. Dearinger A. D. Moridzadeh N. Lu E. D. et al . (2011). Habituation of the C-start response in larval zebrafish exhibits several distinct phases and sensitivity to NMDA receptor blockade. PLoS ONE6:e29132. doi: 10.1371/journal.pone.0029132

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 60

  Santistevan N. J. Nelson J. C. Ortiz E. A. Miller A. H. Kenj Halabi D. Sippl Z. A. et al . (2022). cacna2d3, a voltage-gated calcium channel subunit, functions in vertebrate habituation learning and the startle sensitivity threshold. PLoS ONE17:e0270903. doi: 10.1371/journal.pone.0270903

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 61

  Satterstrom F. K. Kosmicki J. A. Wang J. Breen M. S. De Rubeis S. An J. Y. et al . (2020). Large-scale exome sequencing study implicates both developmental and functional changes in the neurobiology of autism. Cell180, 568–584.e23. doi: 10.1016/j.cell.2019.12.036

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 62

  Schloss S. S. Marshall Z. Q. Santistevan N. J. Gjorcheska S. Stenzel A. Barske L. et al . (2025). Cadherin-16 regulates acoustic sensory gating in zebrafish through endocrine signaling. PLoS Biol.23:e3003164. doi: 10.1371/journal.pbio.3003164

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 63

  Sun F. Zeng J. Jing M. Zhou J. Feng J. Owen S. F. et al . (2018). A genetically encoded fluorescent sensor enables rapid and specific detection of dopamine in flies, fish, and mice. Cell. 174, 481–496.e19. doi: 10.1016/j.cell.2018.06.042

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 64

  Thompson R. F. (2009). Habituation: a history. Neurobiol. Learn. Mem. 92, 127–134. doi: 10.1016/j.nlm.2008.07.011

  • CrossRef
  • Google Scholar

• 65

  Thompson R. F. Spencer W. A. (1966). Habituation: a model phenomenon for the study of neuronal substrates of behavior. Psychol. Rev. 73, 16–43. doi: 10.1037/h0022681

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 66

  Wolf F. W. Eddison M. Lee S. Cho W. Heberlein U. (2007). GSK-3/Shaggy regulates olfactory habituation in Drosophila. Proc. Natl. Acad. Sci. USA.104, 4653–4657. doi: 10.1073/pnas.0700493104

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 67

  Wolman M. Granato M. (2012). Behavioral genetics in larval zebrafish: learning from the young. Dev. Neurobiol.72, 366–372. doi: 10.1002/dneu.20872

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 68

  Wolman M. A. de Groh E. D. McBride S. M. Jongens T. A. Granato M. Epstein J. A. (2014). Modulation of cAMP and ras signaling pathways improves distinct behavioral deficits in a zebrafish model of neurofibromatosis type 1. Cell. Rep. 8, 1265–1270. doi: 10.1016/j.celrep.2014.07.054

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 69

  Wolman M. A. Jain R. A. Liss L. Granato M. (2011). Chemical modulation of memory formation in larval zebrafish. Proc. Natl. Acad. Sci. U S A. 108, 15468–15473. doi: 10.1073/pnas.1107156108

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 70

  Wolman M. A. Jain R. A. Marsden K. C. Bell H. Skinner J. Hayer K. E. et al . (2015). A genome-wide screen identifies PAPP-AA-mediated IGFR signaling as a novel regulator of habituation learning. Neuron85, 1200–1211. doi: 10.1016/j.neuron.2015.02.025

  • Pubmed Abstract
  • CrossRef
  • Google Scholar

• 71

  Zúñiga Mouret R. Greenbaum J. P. Doll H. M. Brody E. M. Iacobucci E. L. Roland N. C. et al . (2024). The adaptor protein 2 (AP2) complex modulates habituation and behavioral selection across multiple pathways and time windows. iScience27:109455. doi: 10.1016/j.isci.2024.109455

  • Pubmed Abstract
  • CrossRef
  • Google Scholar