Anxiolytic-like Effect of Testosterone in Male Rats: GABA(C) Receptors Are Not Involved

OBJECTIVE(S): The effect of testosterone on anxiety-like behaviors has been the subject of some studies. There is evidence that testosterone modulates anxiety via GABA (gama aminobutyric acid) and GABAergic system. The involvement of GABA(C) receptors in those effects of testosterone on anxiety-like behaviors of the rats was investigated in the present study. MATERIALS AND METHODS: A group of rats received subcutaneous injections of testosterone (5, 10 and 20 mg/kg). Two groups of rats received intracerebroventricular injections of either CACA (GABA(C) agonist, 0.125 μg/rat) or TPMPA (GABA(C) antagonist, 3 microg/rat) following administration of testosterone (5, 10 and 20 mg/kg). After the injections, the rats were submitted to the elevated plus-maze test of anxiety. RESULTS: The rats received testosterone alone, showed a decreased in anxiety-like behaviors (P< 0.01). Administration of either CACA or TPMPA did not modify animals’ behavior compared to the rats received testosterone alone. CONCLUSION: The results of the present study showed that administration of testosterone induces anxiolytic-like behaviors in the rats and GABA(C) receptors possibly are not involved in the anxiolytic effect of testosterone.