[Establish and use of an epilepsy model in larval zebrafish]

Epilepsy is a kind of neurogenic diseases with high prevalence and characterized by seizure, brain paradoxical discharge and convulsion in spontaneous, transient, recurrent and uncontrolled manner. Development of new anti-epilepsy drugs requires a new reliable and high-performance animal models in screening of leading compounds. In this study, an epilepsy model in larval zebrafish was established using pentylenetetrazole (PTZ) compound. The results show that PTZ induced epilepsy-like seizure behavior such as irregular circular swimming, exciting locomotion, high swim velocity and convulsion in zebrafish. Expression patterns of two epilepsy-related gene c-fos and lgi1 were analyzed using RT-PCR and in situ hybridization; c-fos was enhanced and extended and lgi1 expression was reduced in PTZ concentration-dependent in the larval brain. When the model larvae exposed to anticonvulsant valproate(VPA), the epilepsy-like symptom decreased or disappeared, the marker genes c-fos and lgi1, as well as NeuN protein recovered to the normal levels. These responses to PTZ and to antiepileptic drug VPA are consistent with the observations in clinical studies and mouse models. Using this model, we evaluated anti-epilepsy activity of compounds Y53 and BMT, two homolog of berberine. The results show that the model larvae seizure triggered by lighting was partly remedied by Y53; and the larval exciting locomotion under the condition of no stimulation was suppressed by BMT. The findings indicate that the zebrafish larval epilepsy model is able to distinguish compounds with different activities in eleptiform seizure. We conclude that the zebrafish epilepsy model may be as a reliable and useful platform in screening of new anti-epilepsy candidates, which is suitable for basic research in epilepsy pathogenesis.