Oxytocin is a complicated hormone. Researchers have found oxytocin to contain properties that can treat several conditions from autism spectrum disorder to intestinal issues. However, as a neuromodulator, it may bring hearts together or help induce aggression, according to the Weizmann Institute of Science. Their findings, published in Neuron, could shed new light on efforts to use oxytocin to treat various mental health disorders, from social anxiety to schizophrenia.
What is Oxytocin?
Also known as the “love hormone,” oxytocin is produced in the hypothalamus and released during sex, childbirth, and lactation to aid reproductive functions. Researchers found it also contains properties used in treating several conditions, including autism spectrum disorder and irritable bowel syndrome. According to research from the Stanford University School of Medicine, oxytocin treatment produces improvement in social behavior among children with autism who have low levels of the hormone. Through the release in the central nervous system, oxytocin also acts as a neuromodulator on multiple brain regions. A recent study conducted at the Weizmann Institute of Science at the University in Rehovot, Israel, reveals that this hormone may be a game-changer in treating various psychiatric conditions.
The “Social Salience” Experiment
The lab group in the Institute’s Neurobiology Department created an experimental setup that allowed them to observe mice in semi-natural living conditions. The interesting addition to this experiment was the inclusion of optogenetics – a method that enables scientists to turn specific neurons in the brain on or off using light. The team took this method a step further and created a compact wireless device that they could use to activate nerve cells by remote control. The department’s optogenetics expert Ofer Yizhar introduced a protein into the mice’s oxytocin-producing brain cells. When light from the device touched those neurons, they became more sensitized to input from the other brain cells in their network.
Previous conflicting research claims that oxytocin mediates pro-social behavior. Some have proposed another theory, termed “social salience,” stating that oxytocin might be involved in amplifying the perception of diverse social cues, resulting in pro-social or aggressive behaviors. According to Biological Psychiatry, the hypothesis also states that the hormone changes various aspects of social behaviors such as empathy, trust, and in-group preference. Social salience also depends on factors such as a person’s character and their environment. To test the theory, the team activated the oxytocin-producing cells in mice’s hypothalamus, placing them first in the semi-natural lab conditions. They then repeated the experiment with mice put in standard lab settings to compare outcomes.
The Results
In the semi-natural environment, the mice exhibited a heightened interest in one another. However, this behavior was quickly met by a rise in aggression. In contrast, increasing oxytocin production in the mice in classic lab conditions resulted in reduced aggression. “In an all-male, natural social setting, we would expect to see belligerent behavior as they compete for territory or food,” stated one of the researchers, Sergey Anpilov. “That is, the social conditions are favorable to competition and aggression. In the standard lab setup, a different social situation leads to a different effect for the oxytocin.”
Potential Pharmaceutical Implications
If oxytocin is more likely a social hormone, what does that mean for its potential pharmaceutical applications? Another researcher on the team Noa Eren, states, “Oxytocin is involved in social behaviors such as making eye contact. However, our work shows that it does not improve sociability across the board. Its effects depend on both context and personality.” What does this imply in terms of treating mental health disorders? If oxytocin is used therapeutically, a much more granular view is needed in research. “If we want to understand the complexities of behavior, we need to study behavior in a complex environment. Only then can we begin to translate our findings to human behavior,” states Eren.
The team does believe that the combination of high-precision optogenetic manipulations in a semi-natural environment is a vital step toward more comprehensive neuro-behavioral research. These studies hold great promise for the search to unveil the mechanisms underlying psychiatric disorders and the potential treatments that may be used to improve these conditions.
