Repeated Maternal Separation in the Neonatal Rat: Cellular MechanismsContributing to Brain Growth Sparing

摘要

Separation of neonates from their dam has been shown to evoke acutely a varietyof biochemical responses, typified by depression of ornithine decarboxylase (ODC) activity. In the current study where rat pups were removed from their nursing dams for 6 h, ODC activities in the liver, heart, kidney and lung were markedly suppressed, but the enzyme in the brain was not altered during the early postnatal ages. These data suggest that the brain was protected from maternal separation insults, a homeostatic response mediated in part, by an increase of circulating corticosterone and glycogen mobilization fromperipheral tissues, particularly the liver. In addition, the authors examined whether these responses were extended to pups who were subject to repeated episodes of maternal deprivation, and whether the stress paradigm might be associated with corresponding changes of cellular growth and maturation.