Learning-specific time-dependent increase in 3H Phorbol ester 12-13 dibutyrate to Protein Kinase C in specific region of the rat brain.

BERNABEU, R., IZQUIERDO, I., CAMMAROTA, M., JERUSALINSKY, D. & MEDINA, J.

BRAIN RESEARCH

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 1995 vol. 685 p. 163 - 168

0006-8993

Several lines of evidence indicate that protein kinase C (PKC) participates in long-term potentiation (LTP) and in certain forms oflearning. Here we describe a rapid, specific and time-dependent increase in [3H]phorbol-12,13-dibutyrate ([3H]PDBu) binding tomembrane-associated PKC in selected brain regions of rats submitted to an inhibitory avoidance task. A quantitative film autoradiographicmethod was used to determine the amount and distribution of membrane-bound PKC in rats sacrificed at various time intervalsafter training. At 0, 30 and 120 min following training there was a prominent increase (up to 200%) in the binding of [3H]PDButhroughout the hippocampus relative to naive, shocked or habituated control groups. No significant changes in [3H]PDBu binding in anybrain region were found at 180 min after training. Similar training-specific increments in the binding of [3H]PDBu were observed in thefrontal, parietal and entorhinal cerebral cortices, amygdala and cerebellum. The maximal effect was seen at 30 min in the CA 2 region ofthe hippocampus (+ 200%) and at 30 and 120 min after training in the amygdala (+ 170%) in comparison to naive control values. Noalterations in [3H]PDBu binding were found in the other brain regions studied. The present findings, together with previous data reportinga similar temporal course in the effects of intrahippocampal or intraamygdala infusion of specific PKC inhibitors on memory, suggest thatPKC activation plays a role in the acquisition and consolidation of an inhibitory avoidance learning.