Stress exposure has been widely related with the development of psychopathologies. Particularly an acute restraint session provokes an enhanced anxiety-like behaviour. We have previously shown that this excessive anxiety is related with an increase of p35 levels selectively in the Basolateral Amygdala (BLA). In the present work, we attempt to elucidate if prior midazolam (MDZ) administration, which normalizes stress-induced anxiogenic behaviour, prevents the increase on p35 expression induced by restraint. Adults Wistar rats (290-320 grs) received a dose of 0.5 mg/kg of MDZ i.p. or vehicle (VEH) and later on subjected to a 30 min restraint session. One day later, animals were behaviourally tested on the elevated plus maze (EPM). Another group of animals received a dose of 0.5 mg/kg of MDZ i.p. or vehicle (VEH) followed by the stressful experience. Thirty minutes after stress rats were sacrificed for the immunohistochemichal analysis of amygdalar nuclei. We found that prior MDZ administration prevents both the increase on p35 levels in BLA and the potentiation of the anxiety-like behavior induced by stress.
