ANTIDEPRESSANT-LIKE EFFECT BY POSTSYNAPTIC 5-HT1A RECEPTOR ACTIVATIONIN MICE

The antidepressant-like effect of odioxan-2-ylmethyl)amino]propoxy}-1, 3-benzodioxole (MKC-242), a novel 5-HT1A receptor agonist, was studied in the forced swimming test in mice injected i.c.v. with 5,7-dihydrox ytryptamine to destroy 5-HT neurons or treated with p-chlorophenylalan ine to inhibit 5-HT synthesis. MKC-242 reduced immobility time of mice pretreated with vehicle and these drugs, although it did not affect t heir locomotor activity. The anti-immobility effect was antagonized by 5-HT1A receptor antagonists such as propranolol and methoxyphenyl)pip erazin-1-yl)-2-phenylpropanamide. These findings support the hypothesi s that postsynaptic 5-HT1A receptors play an important role in the ant idepressant-like effect of 5-HT1A receptor agonists.