Where Oxytocin Is Produced Impacts Effect on Behavior

Oxytocin, also called the love hormone, is known to regulate prosocial behavior such as empathy, trust, and bonding, but it has also been shown to play a role in antisocial behaviors and emotions, including reduced cooperation, envy, and anxiety. A study published earlier this week by UC Davis scientists sheds light on how oxytocin could exert such opposite roles.

According to the team, oxytocin can sometimes have antisocial effects depending on where in the brain it is made. While most oxytocin is produced in the hypothalamus, some oxytocin is produced in the bed nucleus of the stria terminalis, or BNST. The BNST is known for its role in the stress response, and it may play a key role in psychiatric disorders such as depression, addiction and anxiety.

The paper, published in Proceedings of the National Academy of Sciences, show that oxytocin produced in the BNST increases stress-induced social anxiety behaviors in mice. This may provide an explanation as to why oxytocin can sometimes have antisocial effects.

"Before this study, we knew that stress increased the activity of the oxytocin-producing neurons located in the BNST, but we didn't know if they could affect behavior. Our experiments show that production of oxytocin in the BNST is necessary for social anxiety behaviors in California mice," said lead author Natalia Duque-Wilckens.

The researchers were able to show this by using a tool called morpholino-oligos, which, when injected directly into the BNST, prevents oxytocin from being produced in this area. Interestingly, while oxytocin neurons in the BNST are present in both males and females, previous studies from this group showed that social stress has stronger long-term effects on these neurons in females. This is interesting because social anxiety disorders are more common and more severe in women compared to men.