Clozapine treatment during the adolescent period reverses behavioral deficits in a dual-hit mouse model combining prenatal stress and maternal immune activation.

Abstract

OBJECTIVE: Prenatal stress (PNS) and maternal immune activation (MIA) are known risk factors for psychiatric disorders. However, the effects of combining these two factors remain unclear. We investigated the behavioral consequences of dual exposure to PNS and MIA in mice and evaluated whether clozapine treatment during the adolescent period could reverse these changes. METHODS: We established a dual-factor mouse model by administering poly(I:C) (5 mg/kg) on gestational day 9 and applying repeated variable stress from gestational days 14 to 21. Male offspring were tested for prepulse inhibition (PPI), social interaction, and open-field activity. Clozapine (2 mg/kg/day) was administered from postnatal days 35 to 56. Prefrontal cortex protein changes were screened using 2D electrophoresis and MALDI-TOF mass spectrometry. RESULTS: PNS + MIA offspring showed significant deficits in multiple behavioral areas, including a 77% reduction in central zone entries (4.71 ± 2.81 vs. 20.28 ± 6.39 in controls), increased immobility, impaired social interaction, and reduced sensorimotor gating. Clozapine treatment during the adolescent period normalized these behavioral abnormalities without affecting control animals. Proteomic analysis identified several altered proteins, including decreased Sptan1 and increased Glul levels, suggesting changes in the cytoskeleton and glutamate metabolism. CONCLUSION: Combined PNS and MIA exposure produces clear behavioral deficits related to schizophrenia that are effectively reversed by clozapine treatment during the adolescent period. These results support the validity of this dual-hit model and suggest that early pharmacological intervention can be effective during critical developmental periods.