CHANGES OF IMMUNOREACTIVE NEUROPEPTIDE-Y, SOMATOSTATIN AND CORTICOTROPIN-RELEASING FACTOR (CRF) IN THE BRAIN OF A NOVEL EPILEPTIC MUTANT RAT, IHARAS GENETICALLY EPILEPTIC RAT (IGER)

Ihara's genetically epileptic rat (IGER) is a rat mutant with genetica lly scheduled spontaneous convulsions mimicking human Limbic seizures. In the present study, the possible changes of three neuropeptides, ne uropeptide Y (NPY), somatostatin (SRIF) and corticotropin-releasing fa ctor (CRF), in the brains of IGER were investigated. Increased content s of immunoreactive (IR) NPY were found only in the hippocampus of 2-m onth IGERs before developing convulsive seizures, while similar increa ses of IR-NPY were discovered in the striatum and pyriform and entorhi nal cortex as well as hippocampus in 8-month IGERs with repetitive sei zures. There were no significant differences in the brain contents of IR-SRIF and IR-CRF between IGERs and the controls at both ages. These findings indicate an enhanced rate of NPY synthesis in this experiment al model of epilepsy which may play a critical role in the development of epileptogenesis. (C) 1997 Elsevier Science B.V.