Oxytocin: Must be Love on the Brain
Oxytocin cells (in red) form a butterfly shape in the hypothalamus of the brain.
Relationships play an important role in our lives, from families to friendships to romantic partners. These social ties can often affect how we think, feel, and behave; but how do we form these powerful social bonds with one another in the first place? Part of the answer lies in the brain, with a special molecule called oxytocin.
Oxytocin is a hormone that is produced in the hypothalamus of the brain[1]. After it is produced, oxytocin can travel to other areas throughout the brain where it acts as a neurotransmitter, meaning it communicates with other brain cells to produce effects[2]. For example, research has shown that oxytocin release in the nucleus accumbens area of the brain causes prairie voles to form mating pairs, which they then keep for life as monogamous rodents[3]. That’s a powerful bond! Oxytocin is also involved in parenting behaviors in many species, including humans[4]. In humans, higher levels of oxytocin have been associated with heightened social engagement and synchrony between parents and their children[5]. And in other mammals, oxytocin expression in the brain has been shown to cause parents to engage in important offspring care-taking behaviors, like huddling in nests for warmth, grooming offspring, and protecting offspring from potential threats in the environment[6].
Oxytocin is not only influential in the brain; it can also produce effects throughout the rest of the body! When oxytocin travels to the pituitary of the brain, it is released into the bloodstream where it then moves throughout the rest of the body for different functions[2]. For instance, oxytocin released into the bloodstream can have effects on the mammary gland, which stimulates milk release for lactation, and the uterine muscles, which stimulate contractions during birth[7]. In fact, oxytocin (“Pitocin”) is sometimes given to pregnant individuals to encourage contractions for birth[8]! These bodily responses to oxytocin demonstrate just how interconnected our brain and body are.
Oxytocin is involved in many diverse functions that are important in the daily lives of humans and animals alike. From facilitating social bonds with one another to supporting the arrival of new life, oxytocin is a key player in our brain and body. Excitingly, researchers are continuing to uncover more roles that oxytocin is involved in. It truly is the hormone that does it all!
Key Terms
Oxytocin: a hormone and neuropeptide that is produced in the hypothalamus of the brain and involved in many functions, including social behavior
Hormone: chemical messengers that act throughout the body to produce effects on tissues and organs
Neurotransmitter: chemical messengers that act in the brain, communicating messages between brain cells
Monogamous: having only one mate
Pitocin: a synthetic form of oxytocin that can be used to induce labor contractions in pregnant individuals
References
Sofroniew, M. V. (1983). Morphology of vasopressin and oxytocin neurones and their central and vascular projections. In Progress in brain research (Vol. 60, pp. 101-114). Elsevier.
Grinevich, V., Knobloch-Bollmann, H. S., Eliava, M., Busnelli, M., & Chini, B. (2016). Assembling the puzzle: pathways of oxytocin signaling in the brain. Biological psychiatry, 79(3), 155-164.
Young, L. J., & Wang, Z. (2004). The neurobiology of pair bonding. Nature neuroscience, 7(10), 1048-1054.
Olazábal, D. E. (2018). Role of oxytocin in parental behaviour. Journal of Neuroendocrinology, 30(7), e12594.
Gordon, I., Zagoory-Sharon, O., Leckman, J. F., & Feldman, R. (2010). Oxytocin, cortisol, and triadic family interactions. Physiology & behavior, 101(5), 679-684.
Bosch, O. J., & Neumann, I. D. (2012). Both oxytocin and vasopressin are mediators of maternal care and aggression in rodents: from central release to sites of action. Hormones and behavior, 61(3), 293-303.
Augustine, R. A., Seymour, A. J., Campbell, R. E., Grattan, D. R., & Brown, C. H. (2018). Integrative neurohumoural regulation of oxytocin neurone activity in pregnancy and lactation. Journal of neuroendocrinology, 30(8), e12569.
Bell, A. F., Erickson, E. N., & Carter, C. S. (2014). Beyond labor: the role of natural and synthetic oxytocin in the transition to motherhood. Journal of midwifery & women's health, 59(1), 35-42.
