The neurobiology of parental behaviour of the ring dove (streptopelia risoria)

Abstract

The ring dove (Streptopelia risoria) expresses a stereotyped breeding cycle and has been used extensively as a laboratory animal model for studies of avian parental behaviour. Studies were undertaken to identify brain regions of the ring dove involved in the exprcssion of these behaviours, and to determine the central nervous function of the anterior pituitary hormone prolactin and the neuropeptide VIP in incubation behaviour. Quantitative 2-deoxyglucose (2DG) autoradiography at the onset of incubation revealed an increase in uptake in the nucleus preopticus medialis (POM), nucleus tuberis (NT) and nucleus ovoidalis (Ov). Quantitative 2DG autoradiography at late incubation and following treatment with exogenous prolactin revealed a generalised increase in 2D0 uptake in all areas of the brain studied. This effect may be explained by the proliferation of glial cells in response to an increase in the metabolic requirements of neurones involved in the co-ordination and execution of behaviours associated with the breeding cycle. A quantitative analysis of prolactin binding sites at late incubation demonstrated an increase in binding in the NT and a decrease in binding in the nucleus preopticus anterior (POA). Increases in prolactin binding in the NT may control prolactin secretion by the anterior pituitary and may be influenced by the down-regulation of binding sites in the POA. Intracerebroventricular treatment with VIP antiserum following nest deprivation failed to inhibit the resumption of incubatory behaviour after nest replacement, but was found to decrease food consumption. A study of the neuronal bonnections of the POA and NT revealed connections between these two nuclei and visual and auditory relay areas of the brain. These studies demonstrate that the POA and NT are involved in the onset and continuation of incubation behaviour in the ring dove, and that VIP is not the centrally acting factor responsible for the expression of this behaviour.