Anxiogenic effects of brief swim stress are sensitive to stress history.
Stressors that are controllable not only protect an individual from the acute consequences of the stressor, but also the consequences of stressors that occur later. This phenomenon, termed "behavioral immunization", is studied in the rat by first administering tailshocks each of which can be terminated (escapable tailshock) by an instrumental wheel-turn response prior to exposure to a second stressor. Previous research has shown that exposure to escapable tailshock blocks the neurochemical and behavioral consequences of later inescapable tailshock or social defeat stress. Here we explored the generality of behavioral immunization by examining the impact of prior escapable tailshock on the behavioral consequences of cold swim stress. Exposure to a 5min cold-water (19°C) swim caused an anxiety-like reduction in social interaction that was dependent upon 5-HT2C receptor activation. Rats with prior exposure to escapable tailshock did not develop the swim-induced anxiety. Plasticity in the medial prefrontal cortex, a hypothetical neural mechanism underlying behavioral immunization, is discussed.
Department of Psychology & Neuroscience, University of Colorado, Boulder, CO 80309, USA. john.christianson@colorado.edu
John P
JP
Christianson
Robert C
RC
Drugan
Johanna G
JG
Flyer
Linda R
LR
Watkins
Steven F
SF
Maier
D000631:Aminopyridines / Q000494:pharmacology; D000818:Animals; D001007:Anxiety / Q000209:etiology / Q000517:prevention & control* / Q000523:psychology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004597:Electroshock / Q000009:adverse effects; D004924:Escape Reaction / Q000187:drug effects; D005106:Exploratory Behavior / Q000187:drug effects; D046353:Immobility Response, Tonic / Q000187:drug effects; D007211:Indoles / Q000494:pharmacology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013312:Stress, Physiological / Q000502:physiology*; D013315:Stress, Psychological / Q000150:complications*; D013550:Swimming; D013997:Time Factors
C107820:6-chloro-5-methyl-1-((2-(2-methylpyrid-3-yloxy)pyrid-5-yl)carbamoyl)indoline; D000631:Aminopyridines; D007211:Indoles; D017366:Serotonin Receptor Agonists