TY - JOUR
T1 - Persistent stress-induced sensitization of adrenocortical and startle responses
AU - Servatius, Richard J.
AU - Ottenweller, John E.
AU - Bergen, Michael T.
AU - Soldan, Scott
AU - Natelson, Benjamin H.
N1 - Funding Information:
We wish to thank Jennifer L. Gross for technical support. This work was supported by VA medical research funds. Address correspondence and reprint requests to: Dr. John E. Ottenweller, Neurobehaviorai Unit, 127A, Department of Veterans Affairs Medical Center, 385 Tremont Avenue, East Orange NJ 07018-1095. (201) 676-1000 ext 1414, FAX (201) 676-4661. Richard J. Servatius is presently at Princeton University.
PY - 1994/11
Y1 - 1994/11
N2 - We assessed the functional adrenocortical and behavioral state of rats previously exposed to repeated stressor presentations. In Experiment 1, the whole-body startle response to threshold (91 dB) and suprathreshold (96 dB) stimuli was assessed in rats given 3 daily sessions (3DS) of 40, 2-mA tailshocks. The 3DS rats showed an exaggerated startle response to the threshold auditory stimulus 4 days poststressor compared to nonshocked controls (CON). An exaggerated startle response in stressed rats was not evident either 1 day or 10 days poststressor. In Experiment 2, adrenocortical sensitization and behavioral reacivity were assessed in rats exposed to 1 day (1DS) or 3 days of our stress regimen. Stressed rats exhibited elevated basal plasma corticosterone (CORT) levels 1 day poststressor which recovered by 9 days poststressor. Stressed rats also exhibited suppressed open-field activity 4 days poststressor. On the 10th day poststressor, rats were exposed to a single tailshock. The 1DS and 3DS rats showed both a sensitized and prolonged CORT response to stressor reexposure compared to control rats which received only the single tailshock. In addition, on the 11th day poststressor 3DS rats exhibited a moderate recapitulation of the elevated basal CORT levels seen after the initial stressor exposures. Thus, exposure to our stress regimen produces a chronic stress state in rats characterized by persistent behavioral and adrenocortical sensitization, as well as suppressed open-field activity and elevated basal CORT levels. Rats exhibiting a chronic stress state may be appropriate as a model for the study of stress-related psychophysiological illnesses, such as posttraumatic stress disorder.
AB - We assessed the functional adrenocortical and behavioral state of rats previously exposed to repeated stressor presentations. In Experiment 1, the whole-body startle response to threshold (91 dB) and suprathreshold (96 dB) stimuli was assessed in rats given 3 daily sessions (3DS) of 40, 2-mA tailshocks. The 3DS rats showed an exaggerated startle response to the threshold auditory stimulus 4 days poststressor compared to nonshocked controls (CON). An exaggerated startle response in stressed rats was not evident either 1 day or 10 days poststressor. In Experiment 2, adrenocortical sensitization and behavioral reacivity were assessed in rats exposed to 1 day (1DS) or 3 days of our stress regimen. Stressed rats exhibited elevated basal plasma corticosterone (CORT) levels 1 day poststressor which recovered by 9 days poststressor. Stressed rats also exhibited suppressed open-field activity 4 days poststressor. On the 10th day poststressor, rats were exposed to a single tailshock. The 1DS and 3DS rats showed both a sensitized and prolonged CORT response to stressor reexposure compared to control rats which received only the single tailshock. In addition, on the 11th day poststressor 3DS rats exhibited a moderate recapitulation of the elevated basal CORT levels seen after the initial stressor exposures. Thus, exposure to our stress regimen produces a chronic stress state in rats characterized by persistent behavioral and adrenocortical sensitization, as well as suppressed open-field activity and elevated basal CORT levels. Rats exhibiting a chronic stress state may be appropriate as a model for the study of stress-related psychophysiological illnesses, such as posttraumatic stress disorder.
KW - Corticosterone
KW - Open-field activity
KW - Rats
UR - http://www.scopus.com/inward/record.url?scp=0027945174&partnerID=8YFLogxK
U2 - 10.1016/0031-9384(94)90328-X
DO - 10.1016/0031-9384(94)90328-X
M3 - Article
C2 - 7824596
AN - SCOPUS:0027945174
SN - 0031-9384
VL - 56
SP - 945
EP - 954
JO - Physiology and Behavior
JF - Physiology and Behavior
IS - 5
ER -