Stress-induced changes in c-fos immunoreactivity in the porcine brain.

An immunocytochemical method was used to examine expression of c-fos protein in forebrain and brainstem regions of prepubertal pigs (n = 2 per treatment) subjected to various physical stressors (snaring, cold exposure and transport simulation) and of an untreated animal. Each of the stress procedures induced specific nuclear labelling of neurons in the hypothalamus (paraventricular and especially supraoptic nuclei) and small amounts of labelling in some brainstem regions. These results confirm and extend findings obtained in rodents and indicate the potential value of this technique for stress and welfare research in ungulates.