Effects of prenatal stress on behavioural and neurodevelopmental outcomes are altered by maternal separation in the neonatal period

摘要

Background: Chronic psychosocial stress during pregnancy and/or after birth, and the associated elevation in cortisol, is linked with the onset of behavioural disorders in childhood. Previously, prenatal stress has been shown to reduce neurosteroid pathways in the fetus and the levels of the neurosteroid and GABA(A) receptor agonist, allopregnanolone. In late gestation, elevated levels of GABAergic activity increases inhibitory tone and protects against excessive excitation. These levels of allopregnanolone may also contribute to promoting myelination, thus stress-induced suppression of protective neurosteroid levels may disrupt neurodevelopmental processes and can result in reduced myelination. The objective of this study was to examine whether prenatal and postnatal stress reduces levels of inhibitory pathways to result in behavioural, myelin, and GABAergic/glutamatergic pathway deficits in the hippocampus at a postnatal time point in the guinea pig equivalent to childhood in humans.