ABSTRACT
Lactation, the physiological condition during which milk is produced for the purpose of providing nutrition to the offspring, features numerous anatomical, cellular, physiological, and behavioral adaptations, which affect the central nervous system as well as the mammary gland. Although its actions are largely limited to the stimulation of milk ejection, oxytocin (OT), a nine-amino acid peptide released from the brain, is no less essential for a successful lactation, in as much as milk ejections are totally absent in mice bearing a deletion of the OT gene. Although both prolactin (PRL) and OT are released in a reflexive way by the sensory stimulation from the suckling offspring, the patterns of release of these two hormones are quite distinct. Although not studied as extensively, the release of PRL and OT in lactating women exhibits a number of similarities to common animal models, such as the rat.
