AN AMINO-TERMINAL FRAGMENT PEPTIDE OF ACIDIC FIBROBLAST GROWTH-FACTORMODULATES SYNAPTIC TRANSMISSION IN RAT HIPPOCAMPAL SLICES

Effects of acidic fibroblast growth factor (aFGF) fragments such as am inoterminal aFGF (1-15) and carboxyl-terminal aFGF (114-140) on synapt ic transmission were investigated in rat hippocampal slices. Stimulati on was applied to Schaffer collateral/commissural afferents, and evoke d population spikes were recorded in the CA1 pyramidal cell layer. Con tinuous perfusion of slices with aFGF(1-15)slightly decreased the basa l amplitude of population spikes and significantly increased the paire d-pulse facilitation. When brief tetanic stimulation (7 pulses at 100 Hz) was applied 30 min after the perfusion of aFGF (1-15), aFGF (1-15) -treated slices enhanced the magnitude of short-term potentiation afte r the tetanus and facilitated a generation of long-term potentiation. These effects of aFGF(1-15) were dose-dependent. Perfusion of slices w ith aFGF (114-140) had no effect on the basal spike amplitude, paired- pulse facilitation, and shortterm potentiation. Both aFGF (1-15) and a FGF (114-140) had no effect on the DNA synthesis-stimulating activity in BALB/c 3T3-L1 cells. The results suggest that aFGF (1-15), which is not involved in mitogenic activity, is implicated in a modulatory mec hanism of synaptic plasticity.