Translocation of protein kinase Cγ occurs during the early phase of acquisition of food rewarded spatial learning

This study describes the translocation of the brain specific protein kinase C gamma isoenzyme (PKC gamma) in the hippocampus during food rewarded spatial learning. The holeboard test was used for spatial orientation, and immunoblot analysis was used for assessment of PKC gamma in cytosolic, membrane-inserted and membrane-associated fractions. Membrane-associated PKC gamma was increased during early acquisition of spatial learning, but not in a later phase of training. This transient and 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 during the period of novel information processing. The results further promote the hypothesis that the hippocampus is specifically involved in temporal information processing, which requires the engagement of PKC gamma.