The brain prolactin system: involvement in stress response adaptations in lactation

Area of Science:

• Neuroendocrinology
• Neurobiology
• Reproductive Science

Background:

• Prolactin influences emotional and neuroendocrine stress responses.
• The brain prolactin system's role, especially during the peripartum period, is under investigation.
• Pregnancy and lactation are associated with reduced stress responses and altered brain prolactin activity.

Purpose of the Study:

• To review evidence for prolactin's role in regulating brain stress responses.
• To investigate prolactin's anxiolytic and HPA axis inhibitory actions.
• To explore the peripartum activation of the brain prolactin system.

Main Methods:

• Review of existing literature on brain prolactin.
• Studies using chronic intracerebral prolactin infusion.
• Research employing antisense targeting of the prolactin receptor.

Main Results:

• Evidence supports a prolactin receptor-mediated anxiolytic effect in rats.
• Prolactin inhibits the hypothalamic-pituitary-adrenal (HPA) axis and oxytocin system.
• Increased brain prolactin receptor and gene expression observed during the peripartum period.

Conclusions:

• The brain prolactin system is activated in the peripartum period.
• This activation contributes to adaptive changes in stress responsiveness.
• The prolactin system supports crucial reproductive functions through stress modulation.