Hypothalamic monoamine turnover in ring doves ( streptopelia risoria), courting, incubating and brooding young

Abstract

1. The turnovers of hypothalamic 5-hydroxytryptamine (5HT), dopamine (DA) and noradrenaline (NE) were measured in male and female ring doves ( Streptopelia risoria) at three stages of the breeding cycle: courtship, 3 days after pairing; early incubation, 1–2 days after egg laying; and brooding, 1–3 days after the squabs had hatched. 2. In both sexes plasma LH decreased progressively from courtship through incubation to brooding young. Crop sacs were fully developed in doves brooding young but not at other stages of the reproductive cycle, indicating increased concentrations of plasma prolactin. 3. The turnovers of 5HT and DA in both sexes were significantly higher ( P<0.001) in doves brooding young than in birds incubating eggs or nest building. The turnover of DA was higher in females than in males at the onset of incubation. The turnover of NE was lower ( P > 0.01) in females at the onset of incubation than during courtship or brooding. 4. Increased turnover of hypothalamic DA may be more closely related to brooding behaviour than to changes in prolactin or LH secretion. 5. Increased hypothalamic 5HT turnover in brooding doves appears to be more directly related to crop sac development, and by inference increased prolactin secretion, than to depressed plasma LH concentrations.