Neonatal X irradiation: increases in PKC levels underlie behavioural changes

CACERES, L.G; ZORRILLA Z., M. A; URAN, S.L.; GUELMAN, L. R

Congreso; II Reunión Conjunta de Neurosciencias (IIRCN); 2010

Developing Central Nervous System is vulnerable to radiation-induced reactive oxygen species. The consequent oxidative stress is capable to produce changes at different levels in the hippocampus (Hip). We have found that irradiated rats (Rx) have better associative memory in the inhibitory avoidance test (IA). Different molecular targets could be involved in this behavioural change including protein kinase C (PKC), a well known kinase related with memory and learning processes as well as anxiety mechanisms. The aim of the present work was to evaluate the role of PKC in the behavioural changes induced by X-radiation. Neonatal male Wistar rats were X-irradiated (5 Gy) in their cephalic ends up to 48h of postnatal life. Elevated Plus Maze (EPM) as well as PKC total activity and isoforms levels were assessed in Hip of 30-days-old rats. We found a decrease in anxiety, as observed in the EPM, as well as an increase in total PKC activity and PKC β1 isoform levels in the Rx group. These results suggest that PKC could underlie behavioural changes induced by X-rays on the Hip. The better performance in the IA and the decrease in anxiety levels in the Rx group can be attributed to the increase in PKC activity, being the PKC β1 one of the isoforms that would account for this increase.