Adolescent changes in hindbrain noradrenergic A2 neurons in male rats
| Autor: | Laurie Pham, Russell D. Romeo, Ziasmin Shahanoor, Madelyn R. Baker |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Adrenergic Neurons
Male 0301 basic medicine Aging Hypothalamo-Hypophyseal System medicine.medical_specialty Hypothalamus Pituitary-Adrenal System Hindbrain Rats Sprague-Dawley 03 medical and health sciences 0302 clinical medicine Adrenocorticotropic Hormone Internal medicine Male rats medicine Animals Molecular Biology General Neuroscience Solitary tract Rhombencephalon 030104 developmental biology medicine.anatomical_structure Endocrinology Immunohistochemistry Neurology (clinical) Restraint stress Psychology Nucleus 030217 neurology & neurosurgery Developmental Biology Hormone |
| Zdroj: | Brain Research. 1666:11-16 |
| ISSN: | 0006-8993 |
| DOI: | 10.1016/j.brainres.2017.04.012 |
| Popis: | During adolescence, the increased susceptibility to stress-related dysfunctions (e.g., anxiety, drug use, obesity) may be influenced by changes in the hormonal stress response mediated by the hypothalamic-pituitary-adrenal (HPA) axis. We have previously reported that restraint stress leads to significantly prolonged HPA responses in pre-adolescent compared to adult rats. Further, pre-adolescent animals exposed to restraint show greater levels of neural activation than adults in the paraventricular nucleus of the hypothalamus (PVN), a key nucleus integrating information from brain regions that coordinate HPA responses. Here, we examined the potential contribution of the noradrenergic A2 region of the nucleus of the solitary tract (NST) as a contributor to these age-dependent shifts in HPA reactivity. Specifically, we used double-labeled immunohistochemistry for FOS and dopamine-β-hydroxylase (DβH) to measure cellular activation and noradrenergic cells, respectively, before or after restraint stress in pre-adolescent (30 days old) and adult (70 days old) male rats. We also measured the density of DβH-immunoreactive fibers in the PVN as an index of noradrenergic inputs to this area. We found that pre-adolescent animals have a greater number of DβH-positive cells in the A2 region compared to adults, yet the number and percentage of double-labeled DβH/FOS cells were similar between these two ages. We found no differences between the ages in the staining intensity of DβH-immunoreactive fibers in the PVN. These data indicate there are adolescent-related changes in the number of noradrenergic cells in the A2 region, but no clear association between the increased stress reactivity prior to pubertal maturation and activation of A2 noradrenergic afferents to the PVN. |
| Databáze: | OpenAIRE |
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