BRAIN RENIN-ANGIOTENSIN SYSTEM (RAS) IS INVOLVED IN THE LONG LASTING NEURONAL ACTIVATION INDUCED BY AMPHETAMINE

PAZ, M. C.; MARCHESE, N.; BREGONZIO, C.

San Juan

Congreso; Segunda Reunión Conjunta de Sociedades de Biologia de la República Argentina; 2011

Sociedad Argentina de Biología

The enhanced response to psychostimulants relies on time-dependent neuroadaptation involving long-lasting altered behavioral and neurochemical responses. A single exposure to psychostimulants or morphine is sufficient to induce persistent locomotor sensitization, as well as neurochemical and electrophysiological changes in rodents. It provides a unique model to study the bases of long-term behavioral plasticity. Our study tested the hypothesis that Angiotensin II AT1 receptors are involved in the neuroadaptative changes induced by a single exposure to amphetamine (AMPH) and that such changes are related to the development of neuroplasticity. Wistar male rats (250-300 g) were pretreated with an AT1 blocker, candesartan (3 mg/kg po) for five days and after that injected once with AMPH (5mg/kg ip). The Fos immunoreactive neurons (Fos-ir) in response to AMPH (0.5 mg/kg) were determined 3 weeks later. Our results showed an increase in Fos-ir neurons in AMPH pretreated rats in Hippocampus dentate girus and Prefrontal cortex and this response was prevented by the AT1 receptor blockade. The brain RAS should be considered for a better understanding of the mechanisms involved in psychostimulants-induced neuroadaptative changes.