Brief predator odour exposure activates the HPA axis independent of locomotor changes

ALTHOUGH predator exposure has been proposed to elicit both behavioural res ponses and neuroendocrine effects in rodents, results of an increasing numb er studies have failed to consistently detect both of these alterations. We provide a detailed multivariate quantitative assessment of locomotor activ ity levels and plasma levels of adrenocorticotrophic hormone (ACTH) and cor ticosterone of male and female laboratory rats following brief (5 min) expo sure to a predator odour, (2-propylthietane, the main constituent of weasel anal gland secretion). We show that there is a clear distinction between t he behavioural and neuroendocrine responses, with predator odour inducing s ignificant increases in corticosterone and ACTH levels without any signific ant accompanying changes in various locomotor activity measures. NeuroRepor t 10:775-780 (C): 1999 Lippincott Williams & Wilkins.