A.J. Robison and Team Find Gender Distinct Circuit for Depression

November 7, 2019

IIT-affiliated faculty member, A.J. Robison, along with a team of scientists, has found a gender-distinct circuit for depression that activates during stress and is controlled by testosterone. Robison is an assistant professor in the Department of Physiology. 

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Depression affects women nearly twice as much as men, but unraveling the brain’s blueprint that regulates this behavior, let alone identifying specific molecular differences between sexes, has proven difficult.

Michigan State University researchers, however, have found and flipped a switch in the brain, revealing a single circuit in mice that activates during stress and is controlled by testosterone. The results, published in Biological Psychiatry, focus on the activity between neurons in the ventral hippocampus, which become active under stress and emotion, and their activation of nucleus accumbens neurons, critical players in reward and motivation.

“What makes these findings stand out is not only identifying this new circuit,” said A.J. Robison, MSU physiologist and lead author of the study, “but also observing and confirming how it drives different behaviors in males and females.”

Oddly enough, many circuit-specific animal model studies involving depression-related behaviors don’t include female subjects. This gap exists despite sex differences in several depression-related brain regions, including the hippocampus, Robison added.

To help close this void, Robison and a team of MSU scientists focused on this hippocampus-accumbens circuit and saw that the activity in male brains during stress was significantly lower than in females, and this required testosterone. When they removed testosterone, however, the male mice began expressing depression-like behaviors.

Conversely, the team observed increased circuit activity in female brains, but when testosterone was introduced, the neurons quieted, and the female mice became resistant to the depression-like behaviors.

To read more of this story on MSUToday, please visit: https://msutoday.msu.edu/news/2019/scientists-find-gender-distinct-circuit-for-depression/.

Read more about Robison and his research at Michigan Radio: https://www.michiganradio.org/post/women-are-more-likely-be-diagnosed-depression-msu-study-may-help-explain-why. 

The research publication can be found at: https://www.biologicalpsychiatryjournal.com/article/S0006-3223(19)31618-X/pdf.