Oxytocin

Lauren Reader Oxytocin

Oxytocin is a nine amino-acid peptide hormone that is produced in the brain’s hypothalamus and released by the posterior pituitary gland. This compound has been long known to play key roles in female contractions during menstruation and childbirth, milk ejaculation during breast-feeding, and in the formation of maternal bonds. In recent decades, research has been discovered that has demonstrated how oxytocin is also largely responsible for establishing emotional bonds and intense attachment for both males and females (Bowen, 2010). Today, oxytocin is often nicknamed the “cuddle drug” or the “bonding hormone,” and has been a popular topic of interest as it potentially unveils the biophysiological basis behind the emotional bonds formed during human touch and sexual intercourse. ** Oxytocin and Trust ** Little is known about the biological basis of trust, but recent findings have shown that oxytocin is highly influential in social relationships. This can in part be explained by oxytocin’s suppression of certain areas in the amygdala that process fear. In one study, men inhaled either oxytocin or a placebo, and looked at fearful faces and threatening scenes. Amygdala activity was found to be reduced in the group that was administered oxytocin compared to the placebo. With less fear and threat detected by the amygdala, it was deduced that one becomes less defensive and more open to social interactions when oxytocin is present (Sahelian, 2011). In another study, intranasal oxytocin was administered to a group of individuals, and trusting behavior was compared in a trust game with real monetary stakes to their counterparts. From the experiment, researchers were able to conclude that oxytocin substantially increases trust in humans, which thereby greatly increases an individual’s readiness to accept social risks that arise via interpersonal interactions (Kosfeld, Heinrichs, Zak, Ischbache, & Fehr, 2009). Oxytocin’s modulation of anxiety can also explain why mothers are filled with happiness and joy rather than post-traumatic stress disorder after childbirth. Childbirth is long and stressful, and it would make sense that the experience would be overwhelmingly traumatizing. However, the surge of oxytocin released during labor is thought to calm women, relieve the trauma, and promote a maternal bond with their child (University of California, San Francisco, 1999). This modulation of anxiety and fear at the level of the amygdala can explain how oxytocin can be a major factor in a person’s willingness to accept the emotional risk associated with social, romantic, and sexual partners. ** Oxytocin and the Reward System ** With more studies illustrating oxytocin’s impact on relationships, scientists began determining what its role may play in the brain. Studies were conducted on prairie voles, as these mammals are one of nature’s most monogamous species. Scientists found that in faithful voles, oxytocin receptors overlapped with dopamine receptors in the nucleus accumbens- a region in the brain known as one of the essential pleasure centers, or part of the reward circuit. In nonmonogmous voles, oxytocin receptors were located elsewhere. When voles were injected with oxytocin, it was found that the voles formed bonds more quickly than usual. Additionally, the injected voles had a higher level of monogamy than voles without the injection (Johnson & Selim, 2003). This goes to show that forming this committed emotional attachment is marked by pleasure in the brain. The study furthered its research by then administering chemicals that blocked oxytocin receptors in the nucleus accumbens. Scientists found voles practicing in more indiscriminate behaviors without any lasting attachment (Johnson & Selim, 2003). Thus in the absence of oxytocin, emotional attachment and commitment was not encouraged or perceived as pleasurable by the reward circuit. These results have provided key evidence to many researchers’ hypotheses that oxytocin is highly responsible for the pleasure associated with emotional relationships in humans. ** Oxytocin and Touch **

Oxytocin release has been found to be triggered by a variety of environmental stimuli such as skin-to-skin contact. Normal levels of oxytocin in both males and females promote a mild desire to be kissed, held, and touched. However, once someone of romantic interest makes physical contact with an individual, a surge of oxytocin is released. This spike in oxytocin levels causes both psycho logical and biological arousal, and individuals’ desire to be touched further (International AntiAging Systems, 2011). Massage therapy shows this correlation between touch and oxytocin, as it has been found that oxytocin levels are high during the intricate touching and kneading of ones muscles and skin during a massage. Moreover, stress hormones are low, which demonstrates how oxytocin lessens anxiety (Fehrs, 2011). ** Oxytocin and Orgasms ** Nerves in the endogenous zones such as earlobes, neck, and genitals become sensitized from the increases in oxytocin during foreplay and touching. This sensitization from touching creates an intimate bond, as the high oxytocin levels activate the reward circuit in the brain and increase one’s level of trust in their partner. As the oxytocin levels increases, cervical and penile stimulation climbs to higher levels, and the nerves in the genitals fire spontaneously. This rapid firing of the genital nerves eventually leads to an orgasm (International AntiAging Systems, 2011). In men, oxytocin levels are found to quintuple during an orgasm. This number is minute compared to the oxytocin level in females during an orgasm, since women need a significant amount of oxytocin at peak arousal to have an orgasm. Some women’s levels of oxytocin are so high in the brain that multiple orgasms are potentially achievable (International AntiAging Systems, 2011). ** Oxytocin and Intimate Bonding ** The high amount of oxytocin released during intimate touching and intercourse is the chemical component behind sexual communication in loving relationships. Oxytocin decreases levels of fear and anxiety, and increases levels of trust and pleasure, which ultimately promote intimate bonds between couples. This hormone should not be underestimated, as it has the power to break down psychological barriers and reservations individuals may have, making them more vulnerable and sexually receptive. Couples that are in a long and healthy romantic relationship are found to have high levels of oxytocin. The high oxytocin levels trigger the reward pathway, making a positive feedback loop that encourages and promotes additional bonding and intimacy (Kosfeld et al., 2009). However, individuals that become intimate quickly may show different outcomes. The high levels of oxytocin released in a female during sexual stimulation increases her level of social attraction and bonding with her partner. Estrogen additionally increases oxytocin’s effects, making the bond even more pleasurable. In men however, oxytocin released by sexual stimulation is dampened by testosterone, thus many do not experience a reciprocal bond females encounter (Johnson & Salim). Furthermore, the female’s longing for an intimate bond along with the sexual experience in general could potentially overwhelm the male and activate his sympathetic “fight of flight” system. Thus many relationship counselors encourage individuals to become gradually intimate as opposed to all of a sudden. Overtime, men will produce less testosterone and more oxytocin, encouraging emotional attachment (Marazziti, D., Dell’Osso, B., Baroni, S., Mungai, F., Catena, M., Rucci, P., Albanese, F., Giannaccini, G., Betti, L., Fabbrini, L., Italiani, P., Debbio, A., Lucacchini, A., & Dell’Osso, L., 2006).

** References **

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Kosfeld, M., Heinrichs, M., Zak, P. J., Ischbache, U., & Fehr, E. (2009, June 2). Oxytocin Increases Trust in Humans. //Nature//, //435//, 673-676. Retrieved April 7, 2011, from http://www.nature.com/nature/journal/v435/n7042/full/nature03701.html

Marazziti, D., Dell’Osso, B., Baroni, S., Mungai, F., Catena, M., Rucci, P., Albanese, F., Giannaccini, G., Betti, L., Fabbrini, L., Italiani, P., Debbio, A., Lucacchini, A., Dell’Osso, L. (2006, October). A Relationships Between Oxytocin and Anxiety of Romantic Attachment. //Clinical Practice and Epidemiology in Mental Health//, //2//(28). Retrieved April 7, 2011, from http://www.cpementalhealth.com/content/2/1/28

Sahelian, R. (2011). Oxytocin : by Ray Sahelian, M.D., information. //Ray Sahelian, M.D., nutrition expert and best selling author//. Retrieved April 7, 2011, from http://www.raysahelian.com/oxytocin.html

University of California, San Francisco. (1999, July 14). Oxytocin : the hormone of love. //oxytocin.org : the biology of true love//. Retrieved April 7, 2011, from http://www.oxytocin.org/oxytoc/index.html