Therapeutic effects of metabotropic glutamate receptor 5 positive allosteric modulator CDPPB on phencyclidine-induced cognitive deficits in mice.

This study was undertaken to examine the effects of CDPPB (3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide), a positive allosteric modulator (PAM) of metabotropic glutamate receptor 5 (mGlu₅), on cognitive deficits in mice after repeated administration of the N-methyl-D-aspartate (NMDA) receptor antagonist phencyclidine (PCP). In the novel object recognition test, PCP (10 mg/kg/day for 10 days)-induced cognitive deficits in mice were not improved by a single administration of CDPPB (10 mg/kg/day). However, PCP (10 mg/kg/day for 10 days)-induced cognitive deficits in mice were significantly improved by subsequent subchronic (14 days) administration of CDPPB (10 mg/kg/day), but not of CDPPB (1.0 mg/kg/day). This study suggests that PCP-induced cognitive deficits in mice are improved by subsequent subchronic administration of CDPPB. Therefore, mGlu₅ PAMs would be potential therapeutic drugs for cognitive deficits in schizophrenia.