Deer show a gender difference in the neural regulation of appetite by the brain

Abstract

Brain chemicals , called neuropeptides , regulate seasonal changes in reproductive function and appetite. We took brains from red deer males and females at two contrasting seasons of the year and examined specific regions of the hypothalamus microscopically for the presence of cells containing regulatory neuropeptides. This was achieved by immunohistochemistry – i.e. use of highly specific antibodies to label cells – A, for presence of kisspeptin and gonadotropin inhibitory hormone (GnIH) which are neuropeptides involved respectively in the stimulation and inhibition of reproduction, and B, for presence of neuropeptide-Y (NPY) and gamma melanocyte stimulating hormone (MSH) which are involved respectively in stimulation and inhibition of appetite. Brains collected from males and females during the breeding season showed a large presence (200 to 600 versus 50 to 150 per region, breeding and non-breeding seasons respectively) of cells in the hypothalamus containing kisspeptin, which is consistent with the reproductive stimulatory role attributed to this peptide.