Conclusions

Foremost, the potential usefulness of a zebrafish model of pediatric epilepsy should be evaluated with respect to the type of problem to be solved. In the preceding sections, I have tried to provide examples of the features of this model that are clinically relevant. These features include distinct stages of seizure behavior, evidence of abnormal electrical discharge in a CNS structure, seizure-induced expression of c-fos, and AED sensitivity. There are many more features of this model that need to be evaluated, and it is premature to propose that larval zebrafish replace existing rodent seizure models. However, it is not too soon to consider how this simple vertebrate, with striking similarities to commonly used rodent models, may help to open new research directions. Our work was initiated to allow more rapid investigation of genetic modifiers of epilepsy in the developing brain, a fundamental unsolved problem. This goal required establishment of a reliable method to induce and monitor seizures in immature zebrafish. Our methods are described here in detail for the first time, with the intent of encouraging a wider utilization of simple vertebrate systems in pedi-atric epilepsy research.

Acknowledgments

I am grateful for the devotion and effort of my laboratory technicians, graduate students, and postdoctoral fellows, P.A. Castro, S. Guyenet, D.K. Takahashi, D. Botello, J. Greenwood, J. Hsu, M. Dinday, and M.A. Taylor, who have shared in the development of this project. Moral and conceptual support from trusted colleagues, N.M. Barbaro and D.H. Lowenstein, is also gratefully appreciated. I would also like to thank a local zebrafish expert and highly valued collaborator, H. Baier. My research efforts in creating this line of research were supported by grants from the NIH/NINDS, Klingenstein Fund, Epilepsy Foundation of America, and UCSF Innovations in Basic Sciences Fund.

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FIGURE 15—1 Behavioral seizure stages, a: Frame-grabber image of a 7 days post fertilization zebrafish larvae in one well of a 96-well Falcon plate, b: Sample locomotion tracking plots are shown for individual zebrafish in normal Ringer's medium (baseline), during stage I (increased swimming activity), stage II (circling), and stage III (clonus-like convulsions). Blue lines indicate movement; dashed lines indicate rapid convulsive seizure activity (this fish exhibited <25 convulsive episodes). Plots were obtained from recording epochs 2 minutes in duration.

FIGURE 15—1 Behavioral seizure stages, a: Frame-grabber image of a 7 days post fertilization zebrafish larvae in one well of a 96-well Falcon plate, b: Sample locomotion tracking plots are shown for individual zebrafish in normal Ringer's medium (baseline), during stage I (increased swimming activity), stage II (circling), and stage III (clonus-like convulsions). Blue lines indicate movement; dashed lines indicate rapid convulsive seizure activity (this fish exhibited <25 convulsive episodes). Plots were obtained from recording epochs 2 minutes in duration.

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