Pentylenetetrazole induced changes in zebrafish behavior, neural activity and c-fos expression
Section snippets
Animals and maintenance
Zebrafish of the TL strain were maintained according to standard procedures (Westerfield, 1995). All experiments conformed to UCSF and AAALAC guidelines on the ethical use of animals. All animal care procedures were reviewed and approved by the UCSF Institutional Animal Care and Use Committee and were designed to minimize the number of animals used and their suffering. For all experiments zebrafish larvae were maintained in a “normal bathing medium” consisting of 0.03% Instant Ocean (Aquarium
Behavioral seizure activity in larval zebrafish
It is well established that seizures induced in rodents are associated with distinct motor behaviors (Racine, 1972). If zebrafish are to be used for epilepsy research, it is first necessary to establish and define a sequence of seizure-like behaviors. To induce seizures, PTZ (2.5–15 mM) a common convulsant agent, was added to normal bathing medium. Control experiments demonstrated that zebrafish larvae aged 7 dpf swim, infrequently, in small dart-like steps when placed in normal bathing medium.
Discussion
The key finding of this study is that PTZ, a common convulsant, reliably elicited seizures in zebrafish larvae. Previous studies demonstrated the usefulness of rodent PTZ models for AED discovery (Ferrendelli et al., 1989; Shank et al., 1994; Loscher, 2002) and analysis of seizure-generating mechanisms (Mirski and Ferrendelli, 1986; Barkai et al., 1994; Psarropoulou et al., 1994). Our observations indicate that in a simple genetically tractable vertebrate PTZ-induced seizures result in
Conclusions
Genetically tractable model systems such as the bang-sensitive Drosophila mutants have been used to study genes that modify seizure susceptibility (Pavlidis and Tanouye, 1995; Kuebler and Tanouye, 2000; Kuebler et al., 2001). These studies utilize a stimulation-induced afterdischarge model and highlight roles for membrane-bound ion channels in seizure genesis. However, the limitation of this approach is that freely behaving seizure-like activity combined with evidence of abnormal electrical
Acknowledgments
The authors thank N. M. Barbaro, D. H. Lowenstein and S. J. Pleasure for their comments on an earlier version of the manuscript. This work was supported by funds from the UCSF Basic Innovations in Science Fund, Epilepsy Foundation of American Holden Targeted Investigations Program and National Institutes of Health (joint grants to S.C.B. and H.B.).
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