Original articleLong-term adaptations in glucocorticoid receptor and mineralocorticoid receptor mrna and negative feedback on the hypothalamo-pituitary-adrenal axis following neonatal maternal separation
Section snippets
Animals
Animal studies were approved by the Emory University Institutional Care and Use Committee under National Institutes of Health (NIH) Guidelines for the Care and Use of Laboratory Animals. Timed-pregnant Long Evans Crl:(LE)BR rats (Charles River Laboratories, Portage, Michigan) arrived at Emory University on gestation days 11 to 12. All dams were housed in transparent, polypropylene cages containing 2 cm of wood shaving bedding. Animals had ad libitum access to food (Purina Lab Chow) and water in
Plasma ACTH
Two-way ANOVA with repeated measures on time revealed significant effects for both rearing [F(1,8) = 13.4, p < .01) and time [F(6,48) = 2.39, p < .05) on serial plasma ACTH concentrations following acute APS (Figure 1). Although there were no rearing effects for basal am ACTH concentration, we observed marked rearing differences in peak ACTH responses and time of recovery. In HMS15 animals, plasma ACTH concentrations peaked 5 minutes after stressor presentation and quickly declined toward
Discussion
In this study, we report persistent molecular and functional adaptations in central corticosteroid receptors following moderate versus brief handling-maternal separation (HMS) in Long Evans Hooded rats. Previous neuroendocrine studies have shown little difference between rats reared under normal animal facility care and the HMS15 condition (Ladd et al 2000, Plotsky and Meaney 1993), which represents a handling and cage transfer control. Therefore, we did not include a separate animal facility
Acknowledgements
This study was funded by National Institutes of Health Grants MH50113 (PMP) and MH12163 (COL) and the Emory University Silvio O. Conte Center for the Neuroscience of Mental Disease (MH58922).
CBN has received grants from Abbott Laboratories, American Foundation for Suicide Prevention, AstraZeneca, Bristol-Myers-Squibb, Eli Lilly, Forest Laboratories, GlaxoSmithKline, Janssen Pharmaceutica, Merck, National Alliance for Research on Schizophrenia and Depression, National Institute of Mental Health,
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