THE PROJECTION FROM HIPPOCAMPAL AREA CA1 TO THE SUBICULUM SUSTAINS LONG-TERM POTENTIATION

LONG-TERM potentiation (LTP) is a popular model of the synaptic plasti city which may be engaged by the biological processes underlying learn ing and memory. Most available studies of LTP have concentrated on the analysis of LTP occurring in 'early' components of the hippocampal ci rcuit (for example, dentate gyrus and area CA1). We examine here, for the first time, LTP as it occurs in the massive, unidirectional projec tion from CA1 to the subiculum in vivo. We show that this projection s ustains high-frequency stimulus-induced LTP (10 trains of 20 stimuli a t 200 Hz; intertrain interval 2 s; LTP 181 +/- 9% at 30 min post-LTP i nduction). In addition, input-output (I/O) curves show a leftward shif t for all stimulation values. (C) 1998 Rapid Science Ltd.