Changes in daily rhythms of body temperature and activity after a single social defeat in rats

• Published in: Physiology & behavior Vol. 59; no. 4; pp. 735 - 739
• Main Authors: Meerlo, P., De Boer, S.F., Koolhaas, J.M., Daan, S., Van Den Hoofdakker, R.H.
• Format: Journal Article
• Language: English
• Published: Cambridge Elsevier Inc 01.04.1996; New York, NY Elsevier
• Subjects: Activity; Aggressive interaction; Animals; Behavioral psychophysiology; Biological and medical sciences; Body temperature; Body Temperature - physiology; Circadian Rhythm - physiology; Circadian rhythms; Conflict (Psychology); Depression; Fundamental and applied biological sciences. Psychology; Male; Miscellaneous; Motor Activity - physiology; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Rats; Rats, Inbred Strains; Social defeat; Social Dominance; Stress; Telemetry; Circadian rhythms; Body temperature; Depression; Activity; Social defeat; Aggressive interaction; Telemetry; Stress; Affect affectivity; Rat; Rodentia; Male; Biological rhythm; Emotion emotionality; Circadian rhythm; Vertebrata; Mammalia; Animal activity; Social behavior; Social interaction; Conflict; Animal; Agonistic behavior
• ISSN: 0031-9384; 1873-507X
• DOI: 10.1016/0031-9384(95)02182-5

The long-term consequences of social stress on daily rhythms of body temperature and activity in rats were studied by means of radiotelemetry with intraperitoneally implanted transmitters. Rats were subjected to a single social defeat by placing them into the territory of a male conspecific for 1 h. Social defeat caused a sharp subsequent reduction in the amplitude of the daily temperature rhythm, which lasted for at least 4 days. The reduced amplitude was mainly due to higher temperatures during the circadian rest phase, i.e., the light period. Movement activity was less affected, but the decrease in activity during the dark phase after defeat correlated significantly with the temperature increase during the light phase. The stress-induced changes in daily rhythms of body temperature and activity are discussed in terms of their relevance to the role of rhythm-disturbances in the pathogenesis of affective disorders.