Scientists identify a brain region that differs between male and female mice and may influence social behavior

[erronis]

Last edited Mon Jan 26, 2026, 03:36 PM - Edit history (2)

https://medicalxpress.com/news/2026-01-scientists-brain-region-differs-males.html

Note that this study was based on research performed on mice, not humans.
The full article can be found at: https://www.pnas.org/doi/10.1073/pnas.2518703123

Scientists have uncovered a previously unknown cluster of brain cells that may help explain differences in social behavior between males and females. The small neural circuit appears to function like an on/off switch, showing a striking pattern of activity that differs sharply by sex, an unusually clear contrast compared with most known brain sex differences, which tend to be more subtle and overlapping. Researchers also found that the circuit's activity shifts with social and reproductive status, suggesting the brain may use this mechanism to adapt behavior across key life stages.

The new study was led by Dr. Tamar Licht and Dr. Dan Rokni from the Institute of Medical Research Israel-Canada (IMRIC) at the Hebrew University of Jerusalem and is published in the Proceedings of the National Academy of Sciences.

Discovery of a unique brain cluster

The newly identified cluster is located in the medial amygdala, a region of the brain long known to play a central role in social behavior, emotional processing, and reproduction. What makes this cluster especially striking is its binary pattern of activity. In females, the cluster is consistently active under baseline conditions. In males, this brain region is typically inactive and becomes active only after major changes in social or reproductive state.

Before sexual maturation, the region shows similar levels of activity in both males and females; however, after maturation, its activity disappears in males only. The region becomes active again when the male engages in sexual contact, suggesting that social and reproductive context plays a key role in regulating this brain area.

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