Event Abstract

Back to Event

Cerebrospinal fluid from Dementia with Lewy body patients suppresses neuronal network activity

Stephan Theiss1*, Henner Koch2, Walter Maetzler3, 4, Christian Deuschle3, 4, Holger Lerche2 and Marcel Dihné2
  • 1 Heinrich Heine Universität Düsseldorf, Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Germany
  • 2 Universität Tübingen, Department of Epileptology, Germany
  • 3 Universität Tübingen, Department of Neurodegeneration, Germany
  • 4 DZNE, German Center for Neurodegenerative Diseases, Germany

Introduction: Dementia with Lewy bodies (DLB) is a neurodegenerative disease with pathological aggregations of α-synuclein. The clinical course is characterized by early cognitive deficits with Parkinsonism appearing never or no more than 12 months before onset of cognitive symptoms. This course is distinguishing DLB from Parkinson’s disease (PD), in which motor symptoms usually precede cognitive symptoms for more than 5-10 years. The pathology underlying fluctuating cognition in DLB is not well understood. Rapid change over days or even hours favors involvement of soluble factors instead of neurodegenerative processes. Neuroactive substances associated with central nervous system (CNS) disease can be transmitted throughout the brain via the cerebrospinal fluid (CSF) compartment (volume transmission). CSF samples from patients suffering from traumatic brain injury, anti-NMDA-receptor encephalopathy, mild cognitive impairment and Alzheimer’s disease have been shown to induce electrophysiological activity changes when applied to mature networks of rodent neurons long-term cultured on PDL- and laminin-coated microelectrode arrays (MEAs). Patients and Methods: In order to establish a neuronal in vitro model for functional CSF testing, we cultured hippocampal neuronal networks from E17 mice on MEAs with 60 Ti/TiN electrodes (30 µm diameter, 200 µm spacing; Multichannel Systems). After 3 weeks in vitro, networks were exposed to CSF samples from (1) healthy control subjects, (2) Parkinson’s disease (PD) patients without signs of dementia and (3) dementia with Lewy bodies (DLB) patients with fluctuating consciousness. CSF samples were collected by routine diagnostic lumbar puncture, and each group comprised seven individual patients or control subjects. All subjects had normal levels in CSF cell count, albumin and IgG index indicating absence of inflammatory CNS disease and blood-brain-barrier disturbance. All DLB patients suffered from fluctuations in cognition and alertness. The median age of controls, PD and DLB patients was 74, 77 and 75 years. The medians of Mini-Mental State Examination values (0-30) were 30 in controls, 29 in PD and 16 in DLB patients (p<0.001). DLB patients showed significantly lower CSF levels of Aβ1-42 monomers compared to controls and PD patients, while h-tau and p-tau levels associated with neurodegeneration were not significantly different. Three weeks after plating, hippocampal networks on MEAs were functionally mature and exhibited spontaneous neuronal activity (spikes) in synchronous network bursts across nearly all 60 recording electrodes. In each 25-minute experiment with these 21 DIV networks, neuronal network activity was recorded on MEAs first in culture media (5 min), then in artificial CSF (aCSF, baseline, 10 min) and finally in human CSF (either control subject, PD or DLB patient; 10 min, adjusted to pH 7.4). Results: Under aCSF, hippocampal networks exhibited baseline synchronous network burst activity with 2,786 ± 396 spikes/min (mean ± SEM, n=7) in 17 ± 3 network bursts/min. Under human control CSF, activity increased to 5705±868 spikes in 23±4 bursts/min (p=0.014, Mann-Whitney test). In aCSF solution, baseline values of spike and network burst rate, as well as peak firing rate were comparable between all three groups and covered a broad activity range. While applying CSF from PD patients increased spike activity 2.6-fold from aCSF levels—even more than control CSF (2.1-fold), CSF from DLB patients left aCSF activity patterns rather unchanged. We speculate that this statistically significant difference in network responses to PD and DLB patient CSF may be due to additional functional disease related factors in DLB beyond slow neurodegenerative processes. Using the same protocol, we sought to discriminate between CSF from patients with anti-NMDAR-encephalitis and control subjects. In human control CSF, we saw a 3.02±0.42-fold increase of spikes/min (1.45±0.13-fold bursts/min and 3.0±0.7-fold PFR) compared to aCSF. In contrast, NMDAR-CSF elicited no significant changes from aCSF. To examine whether the differential effects of control CSF and NMDAR-pCSF on neuronal network activity were NMDA-receptor mediated, we applied 50 µM of NMDAR antagonist AP5 to hCSF from 8 control subjects (17 recordings in different cultures) and to NMDAR-pCSF samples from 3 patients (8 recordings). Baseline recordings in hCSF or pCSF prior to AP5 application exhibited comparable firing patterns with median 96 network bursts in hCSF and 126 in NMDAR-pCSF groups (p = 0.68). 50 µM AP5 significantly reduced spiking activity 1.5-fold in hCSF (p = 0.001, N = 17) and even 18-fold in NMDAR-pCSF (p = 0.016, N = 8). The number of network bursts remained nearly unchanged in control hCSF, but bursts contained fewer spikes under AP5, while incubation of NMDAR-pCSF with 50 µM AP5 led to sparse spiking only, with no remaining network bursts. Conclusion: Our study suggests that soluble factors exist that are functionally measurable in the CSF of DLB patients. These factors may be associated with fluctuations of cognition, which should be tested in prospective studies. Furthermore, hCSF seems to constitute a physiological environment supporting synchronous neuronal network activity that even compensates partial NMDA-receptor blocking by AP5, while NMDAR-pCSF may lack such a component or contain additional suppressing component(s). Neuronal network activity on MEAs may be a useful in vitro model for the study of pathological candidate factors within human CSF.

Acknowledgements

This work was supported by the German Ministry of Education and Research (BMBF: FKZ
031B0010B) and the European Union (ERA-NET EURO-TRANS-BIO9 project In-HEALTH).

References

Theiss S, Maetzler W, Deuschle C, Lerche H, Koch H, Dihné M. Dementia with Lewy bodies:
cerebrospinal fluid suppresses neuronal network activity. Neuroreport 2017, 28(16):1061-1065
Otto F, Illes S, Opatz J, Laryea M, Theiss S, et al. Cerebrospinal fluid of brain trauma patients inhibits
in vitro neuronal network function via NMDA receptors. Annals of neurology 2009; 66 (4):546-555.
Jantzen SU, Ferrea S, Wach C, Quasthoff K, Illes S, Scherfeld D, et al. In vitro neuronal network
activity in NMDA receptor encephalitis. BMC neuroscience 2013; 14:17

Keywords: Human cerebrospinal fluid, volume transmission, Dementia with Lewy bodies, NMDA receptor, network burst, microelectrode array

Conference: MEA Meeting 2018 | 11th International Meeting on Substrate Integrated Microelectrode Arrays, Reutlingen, Germany, 4 Jul - 6 Jul, 2018.

Presentation Type: Poster Presentation

Topic: Neural Networks

Citation: Theiss S, Koch H, Maetzler W, Deuschle C, Lerche H and Dihné M (2019). Cerebrospinal fluid from Dementia with Lewy body patients suppresses neuronal network activity. Conference Abstract: MEA Meeting 2018 | 11th International Meeting on Substrate Integrated Microelectrode Arrays. doi: 10.3389/conf.fncel.2018.38.00120

Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.

The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.

Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.

For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.

Received: 27 Mar 2018; Published Online: 17 Jan 2019.

* Correspondence: Mr. Stephan Theiss, Heinrich Heine Universität Düsseldorf, Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Düsseldorf, 40225, Germany, theiss@uni-duesseldorf.de