comparison of effects of idazoxan and 5-htp on anxiety with chlordiazepoxide

we studied the effect of the selective alha-2 adrenoceptor blocker idazoxan and precursor serotonin (5-htp) on anxiety-related behavior in rats. the conflict drinking test, and evaluator plus-maze were used as model. idazoxan (2 mg/kg) showed an anticonflict effect, having doses dependently increased the number of punished lickes. 5-htp showed that anxiolytic-like effect in both models. this drug reversed action and produced anxiogenic-like effect at high doses. in contrast, arecholine which is a cholinergic muscarinic agonist drug, produced anxiogenic-like behavior. at 2 mg/kg increased number of entrance (oe) and using time (ot) in open arms in montgomery's test. anxiolytic-like effect of this drug was less than of chlordizepoxide. these results showed that increase release of noradrenaline in synaptic nerve terminals of neurons produced anxiety-related behavior. while high release of serotonin in this area reduced behaviors disorder in rats.