INCREASE IN ACTIVIN BETA-A MESSENGER-RNA IN RAT HIPPOCAMPUS DURING LONG-TERM POTENTIATION

We have used mRNA differential display to isolate genes that are induc ed by neural activity in rat hippocampus. One of these encodes activin beta A subunit. Convulsive seizure caused by kainate significantly in duced the expression of activin beta A mRNA, Furthermore high frequenc y 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 beta A mRNA at the dentate gyrus of urethane-a nesthetized rat, The increase was NMDA receptor-dependent. By contrast the level of inhibin alpha mRNA was not changed following the inducti on of LTP. The results suggest a role for activin in maintenance of ne ural plasticity in the adult brain.