title: Pharmacological evidence that prolactin acts from late gestation to promote maternal behaviour in rabbits.
abstract: We investigated the role of prolactin and suckling stimulation in the expression of maternal behaviour of primiparous rabbits. Bromocriptine (1 mg/kg/day), given to intact mothers across postpartum days 1-5, decreased serum concentrations of prolactin to undetectable levels, reduced crouching, and increased time inside the nest. Failure of maternal nest-building, provoked by bromocriptine injections from pregnancy day 26 to parturition or to postpartum day 5, correlated with a stronger reduction in crouching and an increased time inside the nest, measures of disturbed maternal behaviour, on postpartum days 3 and 5. Preventing suckling by thelectomy did not prevent prolactin release but reduced crouching incidence and increased the time spent inside the nest on postpartum days 3 and 5. Bromocriptine, injected in thelectomized mothers across postpartum days 1-5, further reduced the incidence of crouching and increased the time spent inside the nest on postpartum days 3 and 5. We conclude that prolactin acting prepartum facilitates maternal behaviour initiation in rabbits and, together with pup stimulation, maintains this behaviour across lactation.
authors.affiliation: Centro de Investigación en Reproducción Animal, CINVESTAV-Universidad Autónoma de Tlaxcala, Tlaxcala, Mexico. gglezm@prodigy.net.mx
authors.forename: G
authors.initials: G
authors.lastname: González-Mariscal
authors.forename: A I
authors.initials: AI
authors.lastname: Melo
authors.forename: A F
authors.initials: AF
authors.lastname: Parlow
authors.forename: C
authors.initials: C
authors.lastname: Beyer
authors.forename: J S
authors.initials: JS
authors.lastname: Rosenblatt
mesh_terms: D000818:Animals; D001971:Bromocriptine / Q000494:pharmacology; D005260:Female; D006727:Hormone Antagonists / Q000494:pharmacology; D007743:Labor, Obstetric / Q000502:physiology; D007774:Lactation / Q000187:drug effects; D008425:Maternal Behavior / Q000187:drug effects / Q000502:physiology*; D009043:Motor Activity / Q000187:drug effects; D009425:Nesting Behavior / Q000187:drug effects / Q000502:physiology; D009558:Nipples / Q000502:physiology; D010675:Pheromones / Q000502:physiology; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000097:blood / Q000502:physiology*; D011388:Prolactin / Q000097:blood / Q000502:physiology*; D011817:Rabbits / Q000502:physiology*; D013997:Time Factors
chemical_list: D006727:Hormone Antagonists; D010675:Pheromones; D001971:Bromocriptine; D011388:Prolactin