Abstract
Cognitive processes associated with prefrontal cortex and hippocampus decline with age and are vulnerable to disruption by stress. The stress/stress hormone/allostatic load hypotheses of brain aging posit that brain aging, at least in part, is the manifestation of life-long stress exposure. In addition, as humans age, there is a profound increase in the incidence of new onset stressors, many of which are psychosocial (e.g., loss of job, death of spouse, social isolation), and aged humans are well-understood to be more vulnerable to the negative consequences of such new-onset chronic psychosocial stress events. However, the mechanistic underpinnings of this age-related shift in chronic psychosocial stress response, or the initial acute phase of that chronic response, have been less well-studied. Here, we separated young (3 month) and aged (21 month) male F344 rats into control and acute restraint (an animal model of psychosocial stress) groups (n = 9–12/group). We then assessed hippocampus-associated behavioral, electrophysiological, and transcriptional outcomes, as well as blood glucocorticoid and sleep architecture changes. Aged rats showed characteristic water maze, deep sleep, transcriptome, and synaptic sensitivity changes compared to young. Young and aged rats showed similar levels of distress during the 3 h restraint, as well as highly significant increases in blood glucocorticoid levels 21 h after restraint. However, young, but not aged, animals responded to stress exposure with water maze deficits, loss of deep sleep and hyperthermia. These results demonstrate that aged subjects are hypo-responsive to new-onset acute psychosocial stress, which may have negative consequences for long-term stress adaptation and suggest that age itself may act as a stressor occluding the influence of new onset stressors.
Document Type
Article
Publication Date
2-12-2014
Digital Object Identifier (DOI)
http://dx.doi.org/10.3389/fnagi.2014.00013
Repository Citation
Buechel, Heather M.; Popovic, Jelena; Staggs, Kendra; Anderson, Katie L.; Thibault, Olivier; and Blalock, Eric M., "Aged rats are hypo-responsive to acute restraint: implications for psychosocial stress in aging" (2014). Pharmacology and Nutritional Sciences Faculty Publications. 17.
https://uknowledge.uky.edu/pharmacol_facpub/17
Data Sheet 1
Included in
Medical Nutrition Commons, Medical Pharmacology Commons, Pharmacology, Toxicology and Environmental Health Commons
Notes/Citation Information
Published in Frontiers in Aging Neuroscience, v. 6, no. 13.
© 2014 Buechel, Popovic, Staggs, Anderson, Thibault and Blalock.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.