Maternal behavior prolactin

Knockout of the prolactin receptor, rather than knockout of prolactin, is necessary to explore the role of the hormone and its receptor in maternal behavior because several molecules other than prolactin, including growth hormone (GH) and placental lactogens, may stimulate the prolactin receptor. Disruption of the prolactin receptor gene in a mouse model has allowed for assessment of phenotypes associated with partial and complete prolactin receptor deficits (Goffin et ah, 1999). Prolactin receptor knockout mice have severe reproductive deficits. Heterozygous mothers (receptor —/+) were also unable to lactate (Bridges, 1998). 

Bridges, R.S., Numan, M., Ronsheim, P.M., Mann, P.E., and Lupini, C.E. (1990) Central prolactin infusions stimulate maternal behavior in steroid-treated, nulliparous female rats. Proc Natl Acad Sci USA 87 8003-8007. 

Lucas, B.K., Ormandy, C.J., Binart, N., Bridges, R.S., and Kelly, P.A. (1998) Null mutation of the prolactin receptor gene produces a defect in maternal behavior. Endocrinology 139 4102-4107. 

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