Very mild stress of pregnant rats reduces volume and cell number in nucleus accumbens of adult offspring: some parallels to schizophrenia.

Pregnant rats subjected to very mild stress give birth to pups who, when examined as adults, exhibited behavioral and anatomical anomalies that resemble some aspects of schizophrenia. The nucleus accumbens (NAcc) is reduced in volume by 20.7 +/- 3.4% (p = 0.003) in pups born to mothers who were stressed during pregnancy by injections of either saline or amphetamine in saline. The total number of cells is decreased in proportion to the reduction in volume, so the volume cell density of the NAcc is not changed with treatment. The affected volume is localized in the ventral rostral area of the NAcc. Both males and females are affected, but males are slightly more sensitive to the challenge to the mother. Rats born to mothers stressed in mid-pregnancy appear to provide useful parallels to the fetal developmental hypothesis of schizophrenia and to the brain abnormalities seen in this disease.