Br. Christie et Wc. Abraham, DIFFERENTIAL REGULATION OF PAIRED-PULSE PLASTICITY FOLLOWING LTP IN THE DENTATE GYRUS, NeuroReport, 5(4), 1994, pp. 385-388
THE mechanisms underlying the expression of long-term synaptic potenti
ation (LTP) in the lateral and medial perforant path inputs to the den
tate gyrus were examined in pentobarbital anaesthetized rats. Lateral
path LTP was accompanied by a robust, long-lasting reduction in latera
l path paired-pulse facilitation (PPF). The reduction in PPF lasted fo
r at least 1 h, and remained even after post-tetanic EPSP slopes were
reduced to pre-tetanus levels. The induction of lateral path LTP and t
he corresponding reduction in PPF were blocked by the competitive NMDA
receptor antagonist CPP. Medial path paired-pulse;depression was not
affected by medial path LTP. These data suggest that changes in transm
itter release may contribute more to lateral path than to medial path
LTP.