Repeated phencyclidine administration alters glutamate release and decreases GABA markers in the prefrontal cortex of rats

► Repeated PCP administration increased glutamate release in the PFC of rats. ► The repeated PCP-induced increase in PFC glutamate was blunted compared with that seen after a single PCP injection. ► Repeated PCP administration decreased markers of GABA function in the PFC. ► Clozapine attenuated the PCP-induced changes in glutamate and GABA function.