A drug that facilitates glutamatergic transmission reduces exploratory activity and improves performance in a learning-dependent task.

A recently developed benzamide compound which facilitates glutamate receptor-mediated synaptic responses was used to test behavioral consequences of enhanced glutamatergic transmission. The drug was found to depress exploratory activity by rats in a novel environment. At a dose below threshold for causing such effects, drug-treated and control rats exhibited no evident behavioral differences during the acquisition phase of a radial maze experiment. Yet, when tested 2.5 h later, experimental animals were more likely than controls to choose maze arms that had not been entered during the acquisition session, suggesting that the drug enhanced retention of information about prior choices and the maze environment.