TY - JOUR
T1 - Influence of single or repeated experience of rats with forced swimming on behavioural and physiological responses to the stressor
AU - Dal-Zotto, Silvina
AU - Martí, Octavi
AU - Armario, Antonio
PY - 2000/9/1
Y1 - 2000/9/1
N2 - In the present work behavioural (struggling and immobility), physiological (hypothermia, glycaemia) and endocrine (hypothalamo-pituitary- adrenal (HPA) hormones) response to repeated forced swimming (FS) for 15 days was studied in adult male rats and compared with the response of rats having only one single experience with FS either 1 or 14 days before the last exposure to the stressor. Repeated experiences with FS reduced struggling and increased immobility as compared with stress-naive rats, whereas a single previous exposure to FS, regardless of the time elapsed, had the same, but less marked, effect. Hypothermia followed the same trend. FS-induced hyperglycaemia was not sensitive to a previous single experience, but rather it was totally abolished in chronically stressed rats. Neither a single nor chronic exposure to FS modified the secretion of ACTH in response to the last FS session. However, repeated FS enhanced the speed of recovery of plasma corticosterone as compared to control rats, suggesting a dissociation between the two hormones. The present results revealed great differences in the sensitivity of various behavioural and physiological responses to repeated FS stress and suggest that reduced response to repeated FS, when found, is not a consequence of the time elapsed between exposures but to the repetition of the stressful situation. © 2000 Elsevier Science B.V.
AB - In the present work behavioural (struggling and immobility), physiological (hypothermia, glycaemia) and endocrine (hypothalamo-pituitary- adrenal (HPA) hormones) response to repeated forced swimming (FS) for 15 days was studied in adult male rats and compared with the response of rats having only one single experience with FS either 1 or 14 days before the last exposure to the stressor. Repeated experiences with FS reduced struggling and increased immobility as compared with stress-naive rats, whereas a single previous exposure to FS, regardless of the time elapsed, had the same, but less marked, effect. Hypothermia followed the same trend. FS-induced hyperglycaemia was not sensitive to a previous single experience, but rather it was totally abolished in chronically stressed rats. Neither a single nor chronic exposure to FS modified the secretion of ACTH in response to the last FS session. However, repeated FS enhanced the speed of recovery of plasma corticosterone as compared to control rats, suggesting a dissociation between the two hormones. The present results revealed great differences in the sensitivity of various behavioural and physiological responses to repeated FS stress and suggest that reduced response to repeated FS, when found, is not a consequence of the time elapsed between exposures but to the repetition of the stressful situation. © 2000 Elsevier Science B.V.
KW - Behavioural responses
KW - Psychological responses
KW - Rats
KW - Stressor
U2 - 10.1016/S0166-4328(00)00220-5
DO - 10.1016/S0166-4328(00)00220-5
M3 - Article
SN - 0166-4328
VL - 114
SP - 175
EP - 181
JO - Behavioural Brain Research
JF - Behavioural Brain Research
IS - 1-2
ER -