ASSOCIATIVE LEARNING POTENTIATES PROTEIN-KINASE-C ACTIVATION IN SYNAPTOSOMES OF THE RABBIT HIPPOCAMPUS

Using electrophysiological, biochemical, and autoradiographic techniqu es, changes in protein kinase C (PKC) activity in specific regions of the hippocampus have been previously implicated in classical condition ing of the nictitating membrane response of the rabbit. Here we report that activation of PKC is potentiated 2- to 3-fold in synaptosomes of the hippocampal CA1 and CA2 to -3 regions in rabbits that have underg one classical conditioning of the nictitating membrane response. This potentiation is apparently due to a change in the biochemical properti es of PKC within the synaptosomes and is not a result of an increase i n total PKC activity. This observation correlates a subcellular bioche mical change with classical conditioning of a mammal.