The effects of oxytocin on social anxiety depend on location, location, location
Finding a better route to treating social anxiety disorder may lie in
another part of the brain, researchers suggest

Date:
October 7, 2020
Source:
University of California - Davis
Summary:
The findings of the study 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.



FULL STORY ========================================================================== Studies have long suggested that oxytocin -- a hormone that can also act
as a neurotransmitter -- regulates prosocial behavior such as empathy,
trust and bonding, which led to its popular labeling as the "love
hormone." Mysteriously, oxytocin has also been shown to play a role in antisocial behaviors and emotions, including reduced cooperation, envy and anxiety. How oxytocin could exert such opposite roles had largely remained
a mystery, but a new UC Davis study sheds light on how this may work.


========================================================================== Working with California mice, UC Davis researches showed that the "love hormone" oxytocin can sometimes have antisocial effects depending on
where in the brain it is made. (Mark Chappell/UC Riverside) While most
oxytocin is produced in an area of the brain known as the hypothalamus,
some oxytocin is produced in another brain area known as 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 findings of the study, published this week 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. The lead author is Natalia Duque-Wilckens, a former doctoral researcher at UC Davis who is now at Michigan State University. The
senior author is Brian Trainor, professor of psychology and director of
the Behavioral Neuroendocrinology Lab at UC Davis.

"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 Duque- Wilckens.

Social stress stronger in females 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.

This study further showed that oxytocin-producing neurons in the BNST are connected to brain regions that control anxiety-related behavior. This
was achieved by using a virus to express a fluorescent molecule only in oxytocin neurons.

Remarkably, "simply infusing oxytocin into the parts of the brain that
BNST oxytocin neurons connect to caused ordinarily non-stressed mice to
show social anxiety behaviors as if they had experienced social stress,"
said Trainor.

Previous studies from this and other labs had shown that oxytocin acting
in other areas of the brain, including areas involved in motivated
behaviors, had prosocial effects. This suggests that whether the effects
of oxytocin are pro- or antisocial will largely depend on which areas
of the brain oxytocin is acting in, he said.

"The results are exciting because they provide a potential explanation
for why oxytocin sometimes increases anxiety in humans. The vast majority
of previous work has focused on the neural mechanisms that underlie
the anxiety-reducing effects of oxytocin," Trainor said. "If combined
with further studies of how anxiety is connected with brain circuits
in humans, these results could give us a better understanding of what conditions oxytocin could be beneficial or harmful for treating anxiety."
It's also possible that in some situations, using a drug that blocks the actions of oxytocin could reduce anxiety, he said. In future studies, researchers will try to understand how these neurons activate in response
to stress and why this effect is long-lasting in females, with the final
aim of finding therapeutic strategies that could help patients suffering
from social anxiety disorder.


========================================================================== Story Source: Materials provided by
University_of_California_-_Davis. Original written by Karen
Nikos-Rose. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Natalia Duque-Wilckens, Lisette Y. Torres, Sae Yokoyama, Vanessa A.

Minie, Amy M. Tran, Stela P. Petkova, Rebecca Hao, Stephanie
Ramos- Maciel, Roberto A. Rios, Kenneth Jackson, Francisco
J. Flores-Ramirez, Israel Garcia-Carachure, Patricia
A. Pesavento, Sergio D. In~iguez, Valery Grinevich, Brian
C. Trainor. Extrahypothalamic oxytocin neurons drive stress-induced
social vigilance and avoidance. Proceedings of the National Academy
of Sciences, 2020; 202011890 DOI: 10.1073/ pnas.2011890117 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/10/201007153824.htm

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