7/30/2019 Neurobiology of Social Bonding - Seminar Summary Paragraph

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Natalie Focha

NS M101A

Seminar Summary Paragraph

27 November 2012

4:00 p.m.

The Neuroscience Research Building Auditorium (NRB)

Larry J. Young, Ph.D.

Neurobiology of Social Bonding: Implication for New Treatments for Autism

Dr. Larry J. Young works on understanding DNA at the complex behavior level and is attracted to

social behavior of species. Social behavior is very important and is very evolutionary and ancient (i.e.

mother-child bond). Humans are one of the species that are unique relative to social behavior

because a bond does not only exist between the mother and her offspring; a bond between the male

and female is not unusual beyond the moment of ejaculation. This is one of the reasons that Dr.

Young uses prairie voles in his research as they have a family mating system very similar to humans

and they are socially monogamous (even though they are not sexually monogamous. Monogamy is

important when it takes two to raise a family, as one parent can stay behind to protect the young

while the other parent can hunt for food, and when the population density of the species is love and itis difficult to find a good partner. Dr. Larry studies two hormones that researches believe are

important to forming social bonds: oxytocin and vasopressin. Oxytocin is also known as the maternal

hormone. It promotes uterine contraction during labor, milk ejection during lactation, and maternal

nurturing and bonding. It is believed that oxytocin works to transform female brains; for instance, a

virgin mouse will find mice pups irritating and will avoid them. However, an adult mouse that has

given birth will find their pups very attractive. Vasopressin plays an important role in pair bonding in

male prairie voles and invokes territorial behavior, scent marking, aggression, and pair bonding.

There were also a number of studies that Dr. Young presented; one very interesting study

experimented on how early life experiences affect later social behavior. The method was for three

hours a day the mouse pups were isolated in little cubicles, after which they were transferred back to

their siblings for the rest of the day. After two weeks of these isolation periods, the researcherallowed the pups to reach adulthood in the same environment as their siblings. Observing these

isolated pups after they became adults yielded fascinating results. They found the prairie voles that

underwent the periods of isolation failed to show significant pair bonding. The conclusion drawn was

that brain development during adolescence affects future social bonding caused by the decreased

amount of oxytocin (OT) receptors that are found in the nucleus accumbens. However, it was also

found that pups with a larger amount of OT receptors than other pups are resilient to the early

separation and can still form significant bonding when they reach adulthood. As an aside, at the end

of the lecture, Dr. Young showed us a website that claims that an oxytocin nasal spray can increase

trust in humans which is, of course, not feasible because even if the oxytocin can get past the

membrane in your nasal passage, it would probably increase your trust in other people and not the

other way around.