Phencyclidine-induced cognitive deficits in mice are improved by subsequent subchronic administration of the antibiotic drug minocycline.

Background: The N-methyl-d-aspartate (NMDA) receptor antagonist phencyclidine (PCP)-induced cognitive deficits have been used as an animal model for schizophrenia. This study was undertaken to determine whether the antibiotic drug minocycline could improve PCP-induced cognitive deficits in mice.

Methods: Saline (10 ml/kg/day, s.c., once daily on day 1-5, 8-12) or PCP (10 mg/kg/day, s.c., once daily on day 1-5, 8-12) were administered to mice for 10 days. Subsequently, vehicle (10 ml/kg/day, i.p.) or minocycline (4.0 or 40 mg/kg/day, i.p.) was injected for 14 consecutive days. One day after the final injection, a novel object recognition test was performed.

Results: PCP-induced cognitive deficits in mice were significantly improved by subsequent subchronic (14 days) administration of minocycline (40 mg/kg), but not minocycline (4.0 mg/kg).

Conclusions: This study suggests that minocycline could be a potential therapeutic drug for cognitive deficits in schizophrenic patients.