The Effect of Intracerebroventricular Injection of GABAC Selective Agonist and Antagonist on Anxiety-like Behaviors in Male Rats

The Gamma Amino Butyric Acid (GABA), has three receptors: A, B and C in the body. GABAc receptors play an important role in process of vision, however, their role in other physiological processes yet to be identified. The aim of this study was to evaluate the effect of specific drugs for GABAC agonist and antagonist on anxiety, in male rats. In the present experimental study, the effects of intracerebroventricular (i.c.v) administration of two drugs known as CACA and TPMPA (as the GABAC specific agonist and antagonist, respectively) on anxiety-like behavior in male Wistar rats were determined using elevated plus-maze test model of anxiety. The collected data was analyzed statistically by two and one way ANOVA analysis. Intracerebroventricular administration of CACA with the doses of 0.5, 1, 2 and 4 μg/rat induced anxiogenic effects whereas the i.c.v. administration of TPMPA with the doses of 4 and 6 μg/rat induced anxiolytic effects. Moreover, pretreatment of rats with 3μg/rat of TPMPA before injection of either 0.25, 0.5 or 1 μg/rat of CACA have inhibited the anxiogenic effect of CACA at the dose of 1 μg/rat. The present study showed that, stimulation of GABAC receptors can induce anxiogenic responses contrary to stimulation of A and B receptors. Nevertheless blocking the GABAC receptors contrary to blocking off the other two receptors can induce anxiolytic responses therefore, it may possibly concluded that GABA can induce various effects on anxiety-related behaviors through its receptors. Our results also showed that the anxiogenic effects of CACA was selectively mediated by GABAC receptors.