Oxytocin
Oxytocin (Oxt) is a peptide hormone and neuropeptide. Oxytocin is normally produced by the paraventricular nucleus of the hypothalamus and released by the posterior pituitary. It plays a role in social bonding, sexual reproduction, childbirth, and the period after childbirth. Oxytocin is released into the bloodstream as a hormone in response to stretching of the cervix and uterus during labor and with stimulation of the nipples from breastfeeding. This helps with birth, bonding with the baby, and milk production. Oxytocin was discovered by Henry Dale in 1906. Its molecular structure was determined in 1952. Oxytocin is also used as a medication to facilitate childbirth.
Social cue
Oxytocin has been named "the social hormone". Research done on rats provide strong evidence that social contact enhances oxytocin levels in the brain which then sets the stage for social bonds. In recent years it has been found that inhaling oxytocin through the nasal passage increases trust toward strangers and increases a person's ability to perceive social cues. Activation of face-induced amygdala was found to be increased by oxytocin in women. There have been findings that oxytocin increases occurrence of attention shifts to the eye region of a face which suggests that it alters the readiness of the brain to socially meaningful stimuli. Dopamine neuron from the ventral tegmental area codes the salience of social as well as nonsocial stimuli. Bartz and his colleagues found that the effects of oxytocin is person-dependent, meaning that every individual will be affected differently, especially those who have trouble in social situations. Research done by Groppe and colleagues supports that motivational salience of social cues is enhanced by oxytocin. Oxytocin has been found to increase cues that are socially relevant.