Prenatal stress causes gender-dependent neuronal loss and oxidative stress in rat hippocampus

Our purpose was to investigate the effects of prenatal stress on neuronal changes in the hippocampus and the possible involvement of oxidative stress in female and male rats. Female and male offspring (1-month-old), whose dams were restrained in middle or later pregnant stage (MS or LS), were studied to observe changes in the number of hippocampal neurons and the expression of neuronal nitric oxide synthase (nNOS) in the hippocampus. Both MS and LS induced an increase in the number of nNOS-positive expression in female and male offspring in the hippocampus; however, both MS and LS caused a significant decrease in the number of hippocampal neurons in the female, but not in the male offspring. In addition, significant increases in calcium content and oxidant generation were induced by LS in the hippocampal CA3 region in female rats. These data suggest that prenatal stress can cause oxidative stress and consequent damage to neurons, leading to neuronal loss in the brain of offspring during development. (C) 2004 Wiley-Liss, Inc.