Anxiolytic activity of piracetam, a nootropic agent, following subchronic administration in rodents.

Piracetam (PIR), a cyclic GABA derivative without GABA-mimetic activity, is classified as a nootropic agent, a new class of psychotropic drugs which augment learning acquisition and retention of memory. The present study indicates that PIR has significant anxiolytic activity in rodents following subchronic, but not acute administration, when tested against several paradigms of experimental anxiety. Thus, PIR (250 and 500 mg/kg), administered orally for 7 and 14 days, exhibited anxiolytic activity in the open-field, elevated plus-maze and footshock-induced fighting in paired mice paradigms, as well as in the Vogel's conflict test in rats. In addition, PIR induced significant reduction in rat brain tribulin levels, a putative endocoid marker for anxiety, produced by pentylenetetrazole, an anxiogenic agent. On the contrary, single acute administration of PIR failed to induce any anxiolytic effect. The present study, thus, confirms clinical reports that PIR can induce a delayed antianxiety effect in psychogeriatric individuals and in chronic alcoholism.