Expression of α1bAdrenoceptor mRNA in Corticotropin-Releasing Hormone-Containing Cells of the Rat Hypothalamus and Its Regulation by Corticosterone
Open Access
- 15 November 1999
- journal article
- Published by Society for Neuroscience in Journal of Neuroscience
- Vol. 19 (22) , 10098-10106
- https://doi.org/10.1523/jneurosci.19-22-10098.1999
Abstract
Considerable evidence supports a role for brainstem adrenergic and noradrenergic inputs to corticotropin-releasing hormone (CRH) cells of the hypothalamic paraventricular nucleus (PVN), in the control of hypothalamic–pituitary–adrenocortical (HPA) axis function. However, little is known about specific adrenoceptor (ADR) subtypes in CRH-containing cells of the PVN. Here we demonstrate, using dualin situhybridization, that mRNA encoding α1bADR is colocalized with CRH in the rat PVN. Furthermore, we confirm that these α1bADR mRNA-containing cells are stress-responsive, by colocalization with c-fos mRNA after restraint, swim, or immune stress.To determine whether expression of α1bADR mRNA is influenced by circulating glucocorticoids, male rats underwent bilateral adrenalectomy (ADX) or sham surgery, and were killed after 1, 3, 7, or 14 d.In situhybridization revealed levels of α1bADR mRNA were increased in the PVN 7 and 14 d after ADX, but were not altered in the hippocampus, amygdala, or dorsal raphe. Additional rats underwent ADX or sham surgery and received a corticosterone pellet (10 or 50 mg) or placebo for 7 d. Corticosterone replacement (10 mg) reduced the ADX-induced increase in PVN α1bADR mRNA to control levels, whereas 50 mg of corticosterone replacement resulted in a decrease in PVN α1bADR mRNA as compared with all other groups. Furthermore, levels of plasma corticosterone were significantly correlated (inverse relationship) with α1bADR mRNA in the PVN.We conclude that α1bADR mRNA is expressed in CRH-containing, stress-responsive cells of the PVN and is highly sensitive to circulating levels of corticosterone. Because activation of the α1Badrenoceptor is predominantly excitatory within the brain, we predict that this receptor plays an important role in facilitation of the HPA axis response.Keywords
This publication has 39 references indexed in Scilit:
- In vitro Cytotoxicity of Three 4,9-Diazapyrenium Hydrogensulfate Derivatives on Different Human Tumor Cell LinesChemotherapy, 2000
- Distinct neurochemical populations in the rat central nucleus of the amygdala and bed nucleus of the stria terminalis: Evidence for their selective activation by interleukin-1?Journal of Comparative Neurology, 1999
- Brain Corticosteroid Receptor Balance in Health and DiseaseEndocrine Reviews, 1998
- Evidence for Mineralocorticoid Receptor Facilitation of Glucocorticoid Receptor-Dependent Regulation of Hypothalamic-Pituitary-Adrenal Axis ActivityEndocrinology, 1998
- Neurocircuitry of stress: central control of the hypothalamo–pituitary–adrenocortical axisTrends in Neurosciences, 1997
- Lesions of the Afferent Catecholaminergic Pathways Inhibit the Temporal Activation of the CRH and POMC Gene Expression and ACTH Release Induced by Human Interleukin-1 ? in the Male RatNeuroendocrinology, 1995
- Stress and Interleukin‐1 β‐Induced Activation of c‐fos, NGFI‐B ann CRF Gene Expression in the Hypothalamic PVN: Comparison Between Sprague‐Dawley, Fisher‐344 and Lewis RatsJournal of Neuroendocrinology, 1994
- Stress, Feedback and Facilitation in the Hypothalamo‐Pituitary‐Adrenal AxisJournal of Neuroendocrinology, 1992
- Participation of α1-Adrenergic Receptors in the Secretion of Hypothalamic Corticotropin- Releasing Hormone during StressNeuroendocrinology, 1992
- Catecholamine effects upon rat hypothalamic corticotropin-releasing hormone secretion in vitro.Journal of Clinical Investigation, 1988