Aging alters social preferences through distinct brain mechanisms

The loss of social connectedness as people age increases the odds of cognitive-related disorders and can worsen health outcomes in older populations. But is there a direct relationship between social behavior and cognition? Subhadeep Dutta Gupta, Peter Rapp, and colleagues, from the National Institute on Aging, developed a rat model to probe social cognition in the aging brain. 

As presented in their eNeuro paper, the researchers used 169 young and aged male rats to discover that while older rats were as social as younger ones, a subpopulation largely favored familiar peers over new ones. This preference was unrelated to differences in spatial memory, anxiety-like behavior, or motor abilities. Notably, smelling ability, which is important for social interaction in rodents, was also unrelated to peer preferences. Altering how neurons talk to each other using a noninvasive technique reversed social preferences in older rats, enhancing their approach towards new peers. 

According to the researchers, these findings suggest that aging may influence social behavior through a distinct, potentially modifiable neural system that is at least partly separate from mechanisms underlying age-related spatial memory decline. The researchers emphasize that their preclinical work provides not only a good tool to understand how the brain ages through a "social" lens, but also valuable insight into approaches for maintaining healthy aging. Future work will focus on assessing social networks in the brain as older rats interact with peers to unveil what neural mechanisms support different social behaviors, which could inform treatment interventions early on in the aging process.