The psychogenic effects of prolactin

Area of Science:

• Neuroendocrinology
• Behavioral Neuroscience
• Reproductive Biology

Background:

• Prolactin is a key hormone regulating maternal functions and behavior.
• Hyperprolactinaemia, or elevated prolactin levels, influences brain dopamine and opioidergic systems.
• Prolactin plays a role in learning, immune response, thermoregulation, and corticosterone secretion in mammals.

Purpose of the Study:

• To explore the multifaceted roles of prolactin in maternal functions and behavior.
• To investigate the neurochemical changes associated with hyperprolactinaemia.
• To examine the impact of hyperprolactinaemia on reproductive behaviors and potential psychosomatic responses.

Main Methods:

• Review of existing literature on prolactin's effects on brain regions like the hypothalamus and substantia nigra.
• Analysis of prolactin's influence on neurotransmitter turnover, including dopamine.
• Examination of prolactin's role in reproductive behavior and stress-related psychosomatic reactions.

Main Results:

• Hyperprolactinaemia alters dopamine turnover in brain regions such as the nucleus accumbens and substantia nigra.
• Elevated prolactin stimulates the opioidergic system and may increase portal concentrations of dopamine and oxytocin.
• Hyperprolactinaemia reduces sexual behavior and libido in male rats, and libido in both men and women, with associated low testosterone in men.

Conclusions:

• Prolactin is a critical modulator of maternal behavior and has widespread effects on brain function and neurochemistry.
• Hyperprolactinaemia can lead to significant behavioral changes, including reduced sexual function and potential psychosomatic responses.
• Understanding prolactin's neuroendocrine actions is crucial for comprehending reproductive health and certain behavioral disorders.