Effects of single or repeated immobilization on release of norepinephrine and its metabolites in the central nucleus of the amygdala in conscious rats
Document Type
Journal Article
Publication Date
1-1-1993
Journal
Neuroendocrinology
Volume
57
Issue
4
DOI
10.1159/000126417
Keywords
Dihydroxyphenylacetic acid; Dihydroxyphenylglycol; Methoxyhydroxyphenylglycol; Norepinephrine
Abstract
The release of norepinephrine (NE) and its metabolites in the central nucleus of the amygdala was measured using in vivo microdialysis during immobilization (IMMO) stress in conscious rats. Animals underwent 2-hour periods of IMMO either once or daily for 7 days. Extracellular fluid concentrations of NE, dihydroxyphenylglycol (DHPG), methoxyhydroxyphenylglycol (MHPG), and the dopamine metabolite dihydroxyphenylacetic acid (DOPAC) were measured before, during, and after IMMO. Microdialysate levels of NE and DHPG attained 2-to 3-fold increments during the 1 h of IMMO and declined thereafter, whereas MHPG and DOPAC levels attained maximal levels of about twice basal concentrations during the 2-or 3-h after initiation of IMMO. After the sixth IMMO basal levels of NE, DHPG, MHPG, and DOPAC were decreased, and NE, DHPG, and DOPAC responses during the seventh IMMO failed to attain levels found during the first IMMO, although the absolute changes during IMMO were similar between animals subjected to IMMO once or seven times. The results indicate that acute IMMO increases synthesis, release, and metabolism of NE in the central nucleus of the amygdala and that repetition of IMMO decreases basal catecholamine synthesis and noradrenergic turnover in this brain region, without inhibiting acute noradrenergic responses. © 1993 S. Karger AG, Basel.
APA Citation
Pacak, K., Palkovits, M., Kvethansky, R., Fukuhar, K., Armando, I., Kopin, I., & Goldstein, D. (1993). Effects of single or repeated immobilization on release of norepinephrine and its metabolites in the central nucleus of the amygdala in conscious rats. Neuroendocrinology, 57 (4). http://dx.doi.org/10.1159/000126417