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

Genetic predisposition and environmental factors such as perinatal complica tions are believed to contribute to the etiology of schizophrenia, a disord er involving enhanced CNS dopaminergic activity. This study used a rat mode l to test whether genetic factors and a minor birth complication, i.e. Caes arean section (C-section) birth, interact in producing longterm effects on dopamine-mediated behavior. For this, we compared the effects of vaginal an d C-section birth on amphetamine (AMPT)-induced locomotor activity in strai ns of rats differing in genetic composition. In Sprague-Dawley rats, C-sect ion birth increased AMPT-induced locomotion compared with vaginal birth. By contrast in Lewis rats, C-section birth reduced AMPT-induced locomotion co mpared with vaginal birth. In Fischer rats, AMPT-induced locomotion was inc reased by C-section under maternal anesthesia but decreased by C-section af ter maternal decapitation, compared with vaginal birth. It is concluded tha t a minor birth complication like C-section can have differing long-term ef fects on dopaminergic function in the rat, depending on the genetic composi tion of the individual. NeuroReport 11:639-643 (C) 2000 Lippincott Williams & Wilkins.