Atypical antipsychotic aripiprazole reduces radial-arm maze learning deficits in adult rats following chronic neonatal treatment with MK-801, an NMDA receptor antagonist.

UEHARA J.M.; BIN ISMAIL M.A.; YAMADA K.; ICHITANI Y.

Tokyo

Congreso; The 77th Annual Meeting of the Japanese Society for Animal Psychology; 2017

The Japanese Society for Animal Psychology

We investigated the effects of aripiprazole, an atypical antipsychotic, on spatial learning and working memory ability in adult rats early treated with MK-801, using the radial-arm maze task. Chronic neonatal administration of MK-801 (0.5 mg/kg s.c., twice daily) significantly delayed maze learning, regardless of the pharmacological treatment given during adulthood. However, training extended for 40 trials allowed almost all MK-801-treated animals to reach the learning criterion. In addition, injections of 0 .5 mg/kg aripiprazole (i.p.) before eachbehavioral trial significantly decreased the trials required to learn the task, while a higher dose of 1.0 mg/kg did not produce further improvements. These findings suggest that chronic blockade of NMDA receptors during an early life period impairs spatial working memory in adulthood by significantly delaying, but not preventing, learning. The aforementioned impairment can in turn be reduced by administration of aripiprazole.