Fos-like immunoreactivity in brain regions of domestic rams following exposure to rams or ewes

• Published in: Physiology & behavior 2001-05, Vol.73 (1), p.75-80
• Main Authors: Alexander, B.M, Rose, J.D, Stellflug, J.N, Fitzgerald, J.A, Moss, G.E
• Format: Article
• Language: English
• Subjects: Amygdala - anatomy & histology; Amygdala - physiology; Animals; Behavioral psychophysiology; Biological and medical sciences; Brain - anatomy & histology; Brain - physiology; Brain Mapping; Ewes; Female; Fos-like immunoreactivity; Fundamental and applied biological sciences. Psychology; Male; Miscellaneous; Preoptic Area - anatomy & histology; Preoptic Area - physiology; Proto-Oncogene Proteins c-fos - metabolism; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Rams; Septal Nuclei - anatomy & histology; Septal Nuclei - physiology; Sexual Behavior, Animal - physiology; Sheep; Social Environment; Ventromedial Hypothalamic Nucleus - anatomy & histology; Ventromedial Hypothalamic Nucleus - physiology
• ISSN: 0031-9384; 1873-507X
• DOI: 10.1016/S0031-9384(01)00441-3

Limbic and basal forebrain-hypothalamic regions from male sheep differing in sexual performance were quantified for fos-like immunoreactivity. Rams classified as high-sexually performing (HP), low-sexually performing (LP), and male-oriented (MO) received noncontact sensory stimulation from either ewes in estrus (HP, n=5; LP, n=4; MO, n=4) or other males (HP, n=5; LP, n=4; MO, n=5) for a 4-h period on each of 3 consecutive days. Following exposure to stimulus animals on the third day, rams were euthanized and their brains were perfused with a 1% paraformaldehyde/1.5% glutaraldehyde solution and sections were analyzed for fos-like immunoreactivity. Brain regions analyzed were the medial amygdala (meAMY), medial preoptic area (mPOA), bed nucleus of the stria terminalis (BNST), and ventromedial hypothalamic nucleus (VMH). Fos-like immunoreactivity differed between groups in the mPOA and BNST but not in the meAMY or VMH. LP rams exposed to estrous ewes had more ( P.05) from HP rams exposed to either estrous ewes or other rams. The similar fos-like immunoreactivity in areas important for the display of sexual behavior in HP and LP rams may reflect similar sensory input in these two groups of rams; however, LP rams, in contrast to HP rams, do not appear to respond similarly to the same sensory stimulus.