COMMON FORMS OF SYNAPTIC PLASTICITY IN THE HIPPOCAMPUS AND NEOCORTEX INVITRO

Activity-dependent synaptic plasticity in the superficial layers of ju venile cat and adult rat visual neocortex was compared with that in ad ult rat hippocampal field CA1. Stimulation of neocortical layer IV rel iably induced synaptic long-term potentiation (LTP) and long-term depr ession (LTD) in layer III with precisely the same types of stimulation protocols that were effective in CA1. Neocortical LTP and LTD were sp ecific to the conditioned pathway and, as in the hippocampus, were dep endent on activation of N-methyl-D-aspartate receptors. These results provide strong support for the view that common principles may govern experience-dependent synaptic plasticity in CA1 and throughout the sup erficial layers of the mammalian neocortex.