Differential regulation of glucocorticoid receptor messenger RNA (GR-mRNA) by maternal deprivation in immature rat hypothalamus and limbic regions.

Maternal deprivation (MDep) of neonatal rats significantly influences the hypothalamic-pituitary-adrenal (HPA) axis. This study hypothesized that GR-mRNA modulation constituted an early, critical mechanism for the acute effects of MDep on neuroendocrine stress-responses. GR-mRNA hybridization signal in hippocampal CA1, hypothalamic paraventricular nucleus (PVN) and frontal cortex was significantly reduced immediately following 24 h MDep. In amygdala, cingulate cortex, PVN and CA1, apparent gender-dependent MDep effects on GR-mRNA expression were observed, without significant differences in absolute levels. Thus, rapid, region-specific MDep effects on GR-mRNA expression in HPA-regulating areas are shown, consistent with involvement of GR-expression in mechanisms of MDep influence on HPA tone.