Decrease of neurotrophin-3 mRNA in adult rat hippocampus after pilocarpine seizures.

Neurotrophins such as NT-3 are subject to complex regulation during epileptic seizures. Pilocarpine at a dose of 250 mg/kg induced either limbic seizures (LS) or limbic motor status epilepticus (LMSE) in adult rats. In situ hybridization signals for NT-3 mRNA declined moderately after LS and were nearly lost in LMSE at 3-4 h. Loss of NT-3 mRNA expression does not correlate with cell death and may reflect a functional down-regulation in certain hippocampal neurons.