Febrile seizures in Zebrafish larvae: behavioral analysis and influence in the Pentylenetetrazol - evoked seizures in young adults

Abstract

Animal models have been contributing to a better understanding of the mechanisms underlying epilepsies. Recently, zebrafish larvae were described as a model of hyperthermia-induced seizures presenting abnormal electrographic activities. Despite its significance, this study was conducted using agar-immobilized larvae, and to better characterize the model per se, it is important to describe the effect of transient hyperthermia on free-swimming animals' behavior. This new hyperthermia model can contribute to a better understanding of febrile seizures (FS) in childhood. One important question that can be assessed is whether FS can modify neuronal excitability in the zebrafish brain and consequently alter the Pentylenetetrazole (PTZ)-induced seizures threshold in young adults. Therefore, the objectives of this study are: (I) To establish a protocol for hyperthermia-induced seizures in free-swimming zebrafish larvae, (II) To characterize the behavioral pattern of animals during the seizures, (III) To perform c-fos RNAm quantification in order to assess neuronal activation (IV) To verify whether FS during early developmental stages can modify the threshold for PTZ-induce seizures in adult animals. To achieve these objectives, a hyperthermia protocol in free-swimming zebrafish will be established. The zebrafish behavior will be observed and described in detail. C-fos transcript quantification will be performed using transcriptase reverse quantitative-PCR in order to assess the neuronal activity. Part of the animals exposed to hyperthermia will be separated to reach the age of 30 days (adults), when they will be exposed to different doses of PTZ. Thus, a better characterization of the model for epilepsy studies is expected. (AU)