Colloquially referred to as the ‘love hormone’, its a mammalian pituitary hormone and neurotransmitter that stimulates smooth muscle contraction (e.g., of the uterus during labor) and sensitizes nerves. The posterior pituitary gland, in fact, holds and secretes oxytocin produced by the hypothalamus. Dopamine (the ‘pleasure’ or ‘reward’ hormone) stimulates the production of oxytocin. Animal studies have shown that fewer oxytocin receptors create less attachment in relationships. Increasing during pregnancy and dependent on estrogen for its effects, it activates the flow of breast milk (the let-down response) by stimulating the contraction of muscle cells located near the glands containing milk following the onset of suckling by the newborn. Also the cry of a newborn can stimulate this response. Its reputation as the love hormone, and as being involved in sexual arousal, has generated a large number of studies involving social behavors. For example, it appears to enhance feelings of attachment in adults, as well as the learning of and memory for social information in healthy males. Claims have also been made for its efficacy in the treatment of autism and anorexia nervosa. Oxytocin was first synthesized by Vincent du Vigneaud (1901-1978) in 1953, for which he received the Nobel Prize for Chemistry in 1955. Since then, syntocinon has become widely used in obstetrical practice in order to facilitate the process of labor.
See Attachment, Autism, Dopamine, Estrogen, Hormones, Hypothalamus, Montgomery’s areolar glands, Neurotransmitter, Pituitary gland, Prolactin, Smooth (or involuntary) muscle, Suckling