Genetic factors modulate effects of C-section birth on dopaminergic function in the rat

Genetic predisposition and environmental factors such as perinatal complications are believed to contribute to the etiology of schizophrenia, a disorder involving enhanced CNS dopaminergic activity. This study used a rat model to test whether genetic factors and a minor birth complication, i.e. Caesarean section (C-section) birth, interact in producing longterm effects on dopamine-mediated behavior. For this, we compared the effects of vaginal and C-section birth on amphetamine (AMPT)-induced locomotor activity in strains of rats differing in genetic composition. In Sprague-Dawley rats, C-section birth increased AMPT-induced locomotion compared with vaginal birth. By contrast in Lewis rats, C-section birth reduced AMPT-induced locomotion compared with vaginal birth. In Fischer rats, AMPT-induced locomotion was increased by C-section under maternal anesthesia but decreased by C-section after maternal decapitation, compared with vaginal birth. It is concluded that a minor birth complication like C-section can have differing long-term effects on dopaminergic function in the rat, depending on the genetic composition of the individual.