Corticosterone - an anxiogenic or an anxiolytic agent?

Abstract
Corticosterone (3–12 mg kg−1, i.p., giving rise to plasma corticosterone concentrations from 26.7 to 89.0 μg/100 ml) failed to have a significant anxiogenic action. Instead, corticosterone (3 mg kg−1) had a significant anxiolytic effect in the social interaction test of anxiety. Adrenalectomized rats had very low levels of social interaction; but adrenalectomized rats that had been given replacement corticosterone therapy did not differ from the shamoperated controls. Thus, corticosterone appears to have the opposite effect to that previously reported for ACTH. Possible mechanisms for the observed results are discussed.