Psychosocial stress precipitates psychiatric disorders and cardiovascular disease in vulnerable individuals. The locus coeruleus (LC), a major source of norepinephrine in the brain is implicated in depressive disorders and indirectly increases sympathetic activity. We previously identified two distinct phenotypic responses to social defeat (SD) in rats, characterized by either passive coping (PC, submissive postures) or active coping (AC, upright postures, resistance to defeat). PC was associated with endocrine and behavioral adaptations resembling depression and enhanced inflammation and decreased heart rate variability indicating greater cardiovascular disease risk. Using cardiac telemetry the present study investigated the impact of DSP4 (400ug/rat, icv), a noradrenergic neurotoxin that selectively lesions the LC, compared with vehicle on the cardiovascular response to SD or control manipulations (30 min/day, 7 days) and persistent changes in resting cardiovascular parameters in PC and AC rats. Blood pressure and heart rate significantly increased in AC and PC rats during SD vs controls (day 1). This cardiovascular response to SD was reduced by day 7 in the AC rats, but not PC rats. Interestingly, DSP4 treatment decreased the SD‐induced pressor response in the PC rats. Furthermore, 24 hr telemetry indicated a significant pressor response in PC vs AC rats that persisted for at least 5 days after the 7th and final defeat. Chronic elevations in blood pressure evident in PC rats were also blocked by DSP4 treatment. These data implicate a role for the LC in the enhanced cardiovascular susceptibility evident following social stress in passive coping individuals. Supported by 13BGIA14370026
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.