44-11 Sat Jan 2 Can mating behaviors be maintained in the face of elevated prolactin levels driving parental care? Revisiting the anti-gonadal effect Farrar, VS*; Flores, L; Ornelas Pereira, L; Mushtari, S; Viernes, RC; Calisi , RM; University of California, Davis; UC Davis; UC Davis; UC Davis; UC Davis; UC Davis vsfarrar@ucdavis.edu
In many species, parents may experience tradeoffs between caring for their current brood and exhibiting mating behaviors to begin future reproductive efforts. We examined whether a physiological mediator of parental care, the hormone prolactin, can affect such a reproductive behavioral trade-off. To do this, we experimentally elevated prolactin levels in a biparental bird, the rock dove (Columba livia), after nest loss, from which these birds typically transition from a parental state back to courtship behaviors. Both male and female rock doves exhibit parental care, as well as “lactate” to feed young. We previously found that prolactin-treated doves maintained a parental response to novel chicks after nest loss, compared to vehicle-treated birds. We thus hypothesized that if prolactin maintains a parental state, then it would also delay pairs in their progression through the courtship cycle as they restart their next nest. We further hypothesized that this effect on reproductive behavior would be mediated by changes in gene expression in the hypothalamic-pituitary-gonadal (HPG)reproductive axis. Here, we found that six days after nest removal, prolactin did not significantly affect mating behaviors such as courtship and copulation rates. However, while prolactin did not appear to affect hypothalamic gene expression, neuropeptide receptors in the pituitary and gonadotropin receptors in the male, but not the female, gonads increased with prolactin treatment. This suggests that the HPG axis may be able to maintain reproductive behaviors despite elevated prolactin by compensating with increased responsiveness to hormonal signals. These studies shed light on how continuously-breeding animals may be able to maintain other reproductive functions during parental care.