Oxytocin is a peptide that is produced in the supraoptic (SON) and paraventricular nuclei (PVN) of the hypothalamus and released into circulation from the magnocellular neurons that extend to the posterior pituitary (peripheral system). It is released into the systemic bloodstream in pulsatile form by sensory and other stimuli. Oxytocin is also produced and released from parvocellular neurons in the PVN that project to numerous areas within the brain. It is a hormone but also functions as a neurotransmitter. Oxytocin is found in both males and females. Circulating levels of oxytocin and the number of oxytocinergic neurons in the hypothalamus are independent of sex, and oxytocin release and receptors are similarly induced and distributed in males and females.
Oxytocin has well-known physiological functions during labor and in milk letdown in humans. However, animal research has also demonstrated effects of oxytocin...