COEXPRESSION OF HSP72 AND C-FOS IN RAT-BRAIN FOLLOWING KAINIC ACID TREATMENT

THE relationship between heat shock protein 72 (HSP72) and c-fos gene expression following systemic administration of kainic acid was invest igated by combining immunocytochemistry for HSP72 with in situ hybridi zation for c-fos. Increased HSP72 expression was detected in adult rat hippocampus 4 h after seizure-onset. Transient coexpression of c-fos and HSP72 occurred in neurons that are resistant to kainic acid, where as prolonged coexpression was observed in vulnerable neurons. The spat ial distribution and developmental time course of kainic acid-induced HSP72 expression were similar to those of kainic acid-induced neurodeg eneration. The results demonstrate a relationship between c-fos and HS P72 gene expression and suggest that prolonged co-expression of these genes plays a role in kainic acid-induced neuronal death.