Ibotenic acid lesions of the medial prefrontal cortex potentiate FG-7142-induced attenuation of exploratory activity in the rat.

Six weeks after induction of bilateral sham or ibotenic acid lesions of the medial prefrontal cortex (MPFC), groups of rats were injected with the anxiogenic beta-carboline FG-7142 (15 mg/kg IP) or vehicle (VEH) before exposure to a novel open field. The attenuation of exploratory activity by FG-7142 was markedly enhanced in the MPFC-lesioned rats. The results suggest that the behavioral effects of MPFC lesions may be amplified under stressful conditions. Secondly, the inhibition of exploratory activity by FG-7142 does not depend on its action within the MPFC.