Abstract
In addition to its milk-producing actions in mammals, prolactin (PRL) has been suggested to play an important role in the induction of maternal behavior. The actions of PRL are initiated by its binding to the specific receptors localized in the cell membrane of target tissues. In the present study, we studied the relationship between pup contact-induced parental behavior and serum PRL concentrations and brain PRL Receptor (PRL-R) mRNA expression in female and male rats.
1 . Both female and male rats exposed to foster pups gradually developed parental behavior.
2 . Parental behavior such as crouching, licking, retrieval/grouping and nest building were investigated completely in female rats, but their exhibitions of parental behavior, retrieval/grouping and nest building, were incomplete in male rats.
3 . In both female and male rats displaying those parental behavior, the concomitant increases in serum PRL concentration and brain mRNA expression for long-form PRL-R were observed.
These finding indicated that parental behavior was triggered and maintained in pup - contacted female and male rats through elevated serum PRL levels and induced brain long-form PRL-R.
