Researchers believe they have discovered the part of the brain responsible for social memory. This is the section of the brain which holds memory of familiar people and places. These findings could help in the understanding and treatment of disorders associated with altered social behaviors including autism, schizophrenia and bipolar disorder.
Expanding the understanding of the hippocampus
The hippocampus is the part of the brain that is most associated with memory. Recent studies show that there are active subregions in the hippocampus. One, the dentate gyrus subregion, allows people to distinguish between different environments. Another, the CA3 subregion, enables people to recall memories from partial cues. Finally, the CA1 subregion helps people in all areas of memory. But there is another region which the function has been unidentified, subregion CA2.
Mice showed a lack of curiosity
To test the function of the subregion CA2, researchers selectively blocked the CA2 neurons in specially bred mice. The mice were then exposed to various social environments to see how they reacted. “Normally nice are naturally curious about a mouse they’ve never met; they spend more time investigating an unfamiliar mouse than a familiar one,” noted first author Dr. Frederick L. Hitti. “In our experiment, however, mice with an inactivated CA2 region showed no preference for a novel mouse versus a previously encountered moue, indicating a lack of social memory.” In two other experiments testing memory of vision and smell, the mice were unaffected. The CA2 region appears to be focused on social memory alone.
Important target for behavioral disorders
“Because several neuropsychiatric disorders are associated with altered social behaviors, our findings raise the possibility that CA2 dysfunction may contribute to these behavioral changes,” explained Prof. Steven A. Siegelbaum, senior author of the study. The CA2 subregion may be a new target for the treatment of social disorders.
Source: MedicalNewsToday, Nature