- Poster presentation
- Open Access
Novel perspective on field recordings in zebrafish models of epilepsy
© Dabacan et al. 2015
- Published: 18 December 2015
- Refractory Period
- Optic Tectum
- Focal Epilepsy
- Zebrafish Larva
- Field Recording
Research in Epilepsy relies strongly on animal models, either for describing genetic conditions involved in the disease or for testing potential drugs that might alleviate the symptoms .
In this study, we looked at the differential effect of Pentylenetetrazole (PTZ), a well-known epileptogenic drug , on 5-6 dpf zebrafish larvae of two different genetic conditions: a mutant line, where a gene known to be involved in focal epilepsy was specifically knocked down, as well as control mismatch oligonucleotide-injected zebrafish.
The zebrafish larvae were scored for phenotypic features, including hyperactivity and aberrant locomotion. These phenotypic features were present in all mutant fish recorded, but were absent in the mismatch control. We acquired electrophysiological field recordings from the optic tectum before and after PTZ application and selected a low frequency band of the signal (0.05 - 0.5 Hz). Troughs, representing epileptic events, were extracted and a wide range of analyses were applied: total event count, event time histogram, event duration distributions, inter-event-interval (IEI) distribution, classical and scaled autocorrelations on the field and event signals .
Traditional analysis provided a quantitative evaluation of PTZ-induced epileptic events: an increase in number of epileptic events was observed in mutant fish with respect to control, and the event time histogram showed a more abrupt increase at 32-37 min. after PTZ application, whereas in the control case, the increase was constant throughout the response period. Compared to controls, in mutant fish, PTZ application led to a larger increase in the number of short (0.5-1.5 s) events with small IEI (< 10s).
The characteristics revealed by correlation analysis suggest potentially different mechanisms underlying PTZ-induced epileptic events. We therefore propose that, in addition to the traditional statistics on epileptic events, looking at the temporal characteristics and correlation structure of field recordings may lead to a better classification and understanding of the mechanisms underlying epileptogenesis in various models of epilepsy.
This paper is supported by the Sectoral Operational Programme Human Resources Development POSDRU/159/1.5/S/137516 financed from the European Social Fund and by the Romanian Government.
- Grone B, Baraban S: Animal models of epilepsy: Legacies and new directions. bioRxiv. 2015, 013136-Google Scholar
- Baraban SC, Taylor MR, Castro PA, Baier H: Pentylenetetrazole induced changes in zebrafish behavior, neural activity and c-fos expression. Neuroscience. 2005, 131 (3): 759-768.PubMedView ArticleGoogle Scholar
- Nikolic D, Muresan RC, Feng W, Singer W: Scaled correlation analysis: a better way to compute a cross-correlogram. European Journal of Neuroscience. 2012, 35 (5): 742-762.PubMedView ArticleGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.