TRANSLOCATION OF PROTEIN-KINASE C-GAMMA OCCURS DURING THE EARLY PHASEOF ACQUISITION OF FOOD REWARDED SPATIAL-LEARNING

This study describes the translocation of the brain specific protein k inase C gamma isoenzyme (PKC gamma) in the hippocampus during food rew arded spatial learning. The holeboard test was used for spatial orient ation, and immunoblot analysis was used for assessment of PKC gamma in cytosolic, membrane-inserted and membrane-associated fractions. Membr ane-associated PKC gamma was increased during early acquisition of spa tial learning, but not in a later phase of training. This transient an d apparently temporary intracellular PKC gamma translocation was only observed in the posterior but not in the anterior hippocampus, and was only detected within 10 min after termination of the learning trial. This study supports the idea that PKC gamma is significantly involved in the biochemical events underlying learning and memory, notably duri ng the period of novel information processing. The results further pro mote the hypothesis that the hippocampus is specifically involved in t emporal information processing, which requires the engagement of PKC g amma.