Gender-specific expression of arginine-vasotocin in the chicken brain.

摘要

The avian neuropeptide arginine vasotocin (AVT), originally characterised as the antidiuretic hormone, is produced by neurosecretory cells within the brain. Major locations are the preoptic area, including the supraoptic nucleus, the hypothalamic paraventricular nucleus and the limbic bed nucleus of the stria terminalis (BnST). Magnocellular AVT neurons of the hypothalamic locations project to the neurohypophysis and make a major contribution to the peptide content in the circulation. Major physiological functions of circulating AVT are regulation of the hydromineral balance, as well as its contribution to reproductive events like oviposition. Parvocellular AVT neurons located in the limbic BnST are quite different in their properties and, most likely, functions. In these neurons, the AVT gene is expressed in a sexually dimorphic manner and are found solely in males. During embryogenesis, these neurons occur in both sexes and are subjected to sexual differentiation during the perinatal stages of ontogeny. Embryonic oestrogen may exert organisational effects on specific sex dimorphic peptidergic circuits in the chicken brain. AVT is involved in the modulation of different aspects of reproductive behaviour. Moreover, evidence coming from ethological, physiological and anatomical studies strongly suggests a role for the vasotocinergic system in various forms of adaptive responses.