Drug action on the "grasping" reflex and on swimming endurance; an attempt to characterize experimentally antidepressant drugs

The length of time rats could remain suspended from a horizontal rod was measured. Chlorpromazine and diazepam reduced grasping. Low doses of pentobarbital, urethan, imipramine, amitriptyline, doxepine, butriptyline, iproniazid and amphetamine increased grasping time. For imipramine, amitriptyline, doxepine, iproniazid and amphetamine a linear correlation, log dose against increase of grasping time, was found. Swimming endurance was increased by amphetamine and was not modified by imipramine, amitriptyline, doxepine, iproniazid, urethan or pentobarbital. The possibility is discussed that the grasping reflex may be useful to characterize experimentally drugs with antidepressant properties.