There’s probably a lot you might not remember about your trip, like details about the surrounding landscape, regardless of how many times you’ve been there before. One thing the brain rarely gets credit for is its ability to separate the important details — the right exit; the landmarks that come before it and when you know if you’ve gone too far — from the mundane ones. It may owe this ability, at least in part, to oxytocin.
Catherine Dulac, the Higgins Professor of Molecular and Cellular Biology at Harvard University, conducted a research effort that suggests oxytocin may actually serve as a modulator for the brain — capable of sorting through a number of social signals. According to Dulac and her team of researchers, the compound hones in on certain stimuli while filtering others out, as though adjusting the picture on a television set, altering the frequency constantly at each moment.
For their project, Dulac and her colleagues observed lab mice, following a well-known pattern of behavior seen in labs — the way in which male mice prefer to congregate with females. This behavior isn’t just due to these little rodents trying to break the ice, this mannerism is encoded into their brains. They need the interaction almost as much as they need food and water.
The female mice give off chemical signals known as pheromones. The males pick up on this and, as found in the study, the neurons in their medial amygdala spike with activity. The number of times mice made nose to nose contact was an indicator of rewarding social interaction. The same group of mice were then exposed to the pheromones produced by other males, and the medial amygdala indicated very little stimulation.
Following these trials, Dulac was able to isolate the gene needed to produce oxytocin, and switch the gene off. Once the signal was turned off, the neural signaling disappeared — as did their desire to socialize. Dulac’s team also found that the signaling effect occurs on and off, from moment to moment. A failure in the switch could potentially be one of the factors that causes depression in humans, when depressed people no longer find joy from interacting with other people.
“There may be many different regulators,” says Dulac, reflecting on the study. “Oxytocin might be one of a whole realm of modulators, each of which are important in a particular circumstance. That therefore gives the animal a great deal of plasticity in terms of engaging in a particular behavior, so it’s not the case that each time the animal encounters a particular stimulus it will react in exactly the same way. Depending on the state of the brain and the release of these neurotransmitters, the animal can boost its behavior toward the stimulus or ignore it.”
She hopes that the team’s observations could be used to develop further treatments in depression if similar patterns are seen in humans. Yet another study, published in the Journal of Medicinal Chemistry, reports the discovery of a new compound the first known variation of a chemical that rewards the mouse’s brain for interacting with other mice. Some of the mice in the sample group exhibited symptoms similar to people with autism spectrum disorders (repetitive behaviors, deficient communication skills, and low levels of social interaction).
The study’s lead researcher, Marcel Hibert, knew of oxytocin’s ability to help improve the lives of some patients with autism. Because the oxytocin cannot be administered by oral tablets and quickly breaks down when given by injection before it can reach the brain, Hibert and his colleagues sought another compound in the brain that could mimic the abilities of oxytocin — just enough to activate the brain’s receptors and set them active.
The candidate, LIT-001, binds to oxytocin as well as vasopressin, which serves as an antidiuretic hormone. Hibert and researchers established that they both share a similar component, known as benzoyl benzazepine. After several molecular models were tested, they found one that offered benefits similar to oxytocin but none of the drawbacks that made it difficult to synthesize as medicine.
This article was first published in Brain World Magazine’s Winter 2019 issue.
More From Brain World
- Assimilated: The Clout of Cults on Identity
- How Stress Affects Your Thinking — And How to Address It
- Know Your Brain: The Pituitary Gland — Understanding The Master Gland
- The Love Revolution: How A New Brain-Centered Therapy May Save Relationships
- Namaste: Practicing Yoga for the Aging Brain
- Why Are Some People More Positive Than Others?
