Body surface temperature of rats reveals both magnitude and sex differences in the acute stress response

• DOI: 10.1016/j.physbeh.2023.114138
• Publication Date: 2023-03-05T07:04:00Z
• Authors: Chanakarn Wongsae...; Dominic J. McCaff...; Neil P. Evans; Dorothy E.F. McKe...; Ruedi G. Nager
• Keywords: Stressor; Corticosterone

Understanding how biological markers of stress relate to stressor magnitude is much needed and can be used in welfare assessment. Changes body surface temperature measured using infrared thermography (IRT) as a marker physiological response acute stress. While an avian study has shown that changes reflect the intensity stress, little known about responses stressors different magnitudes its sex-specificity mammals, they correlate with hormonal behavioural responses. We IRT collect continuous measurements tail eye adult male female rats (Rattus norvegicus), for 30 minutes after exposure one three (small cage, encircling handling or rodent restraint cone) minute, cross-validated thermal plasma corticosterone (CORT) To obtain individual baseline temperatures were imaged test arena (to which habituated) seconds before being exposed stressor. In stressors, initially decreased then recovered to, overshot temperature. Tail dynamics differed between stressors; restrained small cage was associated smallest drop temperature, rats, fastest recovery, both sexes. Increases only distinguished early females. The post increase greater right males left sexes may have been CORT. These results line observed changes, movement higher immobility encircling. well CORT concentrations did not return pre-stressor levels observation period, conjunction occurrence escape-related behaviours rats. suggest are more vulnerable compared emphasise importance future investigations magnitude. This demonstrates induced mammalian indicate sex differences Thus, potential become non-invasive method assessment unrestrained mammals.