One Health, Two Species: Linking Domestication to Cognitive Aging in Dogs and Humans.

This commentary explores the parallel neuroanatomical and neurobiological evolution that ultimately led to modern dogs and humans, through domestication and self-domestication, respectively. The selective pressures for benignness and enhanced prosociality have reshaped brain anatomy and cognitive architecture in both Canis familiaris and Homo sapiens, leading to analogous changes including a reduction in limbic system volume and expansion of the prefrontal cortex, critical for executive control and social cognition. From a molecular point of view, shared genetic and epigenetic underpinnings of these adaptations and their implications gave rise to parallel trajectories in brain aging; notably, the emergence of canine cognitive dysfunction. Interestingly, this canine age-related cognitive decline presents significant overlaps with Alzheimer's disease in terms of both behavioral presentation and underlying pathology. In the context of a One Health perspective, the profound influence of shared environmental exposures, such as urbanization, pollutants, and stressors, on neurodevelopment, cognitive aging, and disease susceptibility offers a compelling translational model for understanding brain health within intertwined ecological and social contexts.