INVOLVEMENT OF 2 ISOFORMS OF SNAP-25 IN THE EXPRESSION OF LONG-TERM POTENTIATION IN THE RAT HIPPOCAMPUS

INDUCTION of long-term potentiation (LTP) in the hippocampus is associ ated with changes in expression of a variety of different proteins and is thought to be the mechanism which underlies synaptic plasticity. T he 25 kDa synaptosomal-associated protein (SNAP-25) is a presynaptic p rotein which is involved in neurotransmitter exocytosis at the nerve t erminal. Two isoforms of SNAP-25 have so far been identified (a and b) which differ in their distribution and developmental regulation. Usin g in situ hybridization, we demonstrated that the mRNA levels of the t wo isoforms of this protein are increased 2 h after the induction of L TP in granule cells of the dentate gyrus following high frequency stim ulation of the perforant path in vivo. These observations further demo nstrate the involvement of both isoforms of SNAP-25 in functional syna ptic plasticity, although their exact roles have yet to be fully deter mined.