title: Stress and Drug Dependence Differentially Modulate Norepinephrine Signaling in Animals with Varied HPA Axis Function.
abstract: Previous work has demonstrated the importance of genetic factors and stress-sensitive circuits in the development of affective disorders. Anxiety and numerous psychological disorders are comorbid with substance abuse, and noradrenergic signaling in the bed nucleus of the stria terminalis (BNST) is thought to be a source of this convergence. Here, we examined the effects of different stressors on behavior and norepinephrine dynamics in the BNST of rat strains known to differ in their HPA-axis function. We compared the effects of acute morphine dependence and social isolation in non-anxious Sprague Dawley (SD) rats, and a depression model, Wistar-Kyoto (WKY) rats. We found a shared phenotype in drug-dependent and singly housed SD rats, characterized by slowed norepinephrine clearance, decreased autoreceptor function, and elevated anxiety. WKY rats exhibited changes in anxiety and autoreceptor function only following morphine dependence. To ascertain the influence of LC inhibition on this plasticity, we administered the LC-terminal-selective toxin DSP-4 to SD and WKY rats. DSP-4-treated SD rats demonstrated a dependence-like phenotype, whereas WKY rats were unchanged. Overall, our findings suggest that individuals with varying stress susceptibilities have different noradrenergic signaling changes in response to stress. These changes may establish conditions that favor stress-induced reinstatement and increase the risk for addiction.
authors.affiliation: Department of Chemistry, Center for Neuroscience at the University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: Megan E
authors.initials: ME
authors.lastname: Fox
authors.affiliation: Department of Chemistry, Center for Neuroscience at the University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: R Isaac
authors.initials: RI
authors.lastname: Studebaker
authors.affiliation: Department of Chemistry, Center for Neuroscience at the University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: Nathaniel J
authors.initials: NJ
authors.lastname: Swofford
authors.affiliation: Department of Chemistry, Center for Neuroscience at the University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: R Mark
authors.initials: RM
authors.lastname: Wightman
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001596:Benzylamines / Q000633:toxicity; D004195:Disease Models, Animal; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D018782:Maze Learning; D009021:Morphine Dependence / Q000378:metabolism*; D014179:Neurotransmitter Uptake Inhibitors / Q000633:toxicity; D009638:Norepinephrine / Q000378:metabolism*; D010913:Pituitary-Adrenal System / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011921:Rats, Inbred WKY; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013315:Stress, Psychological / Q000378:metabolism*
chemical_list: D001596:Benzylamines; D014179:Neurotransmitter Uptake Inhibitors; C012102:DSP 4; D009638:Norepinephrine