Reduced Activity of Glutamatergic Neurons in the Prelimbic Medial Prefrontal Cortex Underlies the Inherent Aging-Related Physiological Reduction in Social Dominance

Abstract Human society is aging, and the percentage of the population of older adults is increasing at an unprecedented rate. It is increasingly appreciated that social behaviors change with aging. One such example is the possible aging-related reduction in dominance status. This change has been thought to underlie older adults’ peculiar vulnerability to fraud, which has become a major challenge in the present aging society. However, whether this change is an inherent physiological process, and, if so, its underlying microscopic physiological mechanism, is not known. This study used groups of mice in a design that minimized effects that could confound any inherent process of dominance and verified that social dominance does inherently reduce with aging. This study further identified an aging-related microscopic functional alteration, that is, a reduction in the activity of glutamatergic pyramidal neurons in the prelimbic medial prefrontal cortex; and established that this reduction in neuronal activity serves as an intrinsic physiological mechanism underlying the macroscopic aging-related reduction in dominance. This study, by exploiting modern neurobiological techniques, sheds light on our understanding of human social behaviors during aging and may help develop strategies to counter related social challenges among the older adults population.