We have used mRNA differential display to isolate genes that are induced by neural activity in rat hippocampus. One of these encodes activin βA subunit. Convulsive seizure caused by kainate significantly induced the expression of activin βA mRNA. Furthermore high frequency stimulation (HFS) of perforant pathway, which produced a persistent long-term potentiation (LTP) (> 10 h), caused a marked increase at 3 h in the level of activin βA mRNA at the dentate gyrus of urethane-anesthetized rat. The increase was NMDA receptor-dependent. By contrast the level of inhibin α mRNA was not changed following the induction of LTP. The results suggest a role for activin in maintenance of neural plasticity in the adult brain.
