DO DADS MATTER? PATERNAL PRECONCEPTION TACTILE STIMULATION SHAPES OFFSPRING BRAIN AND BEHAVIOR FROM INFANCY TO ADULTHOOD

Parental experiences before conception can influence offspring neurodevelopment, yet the role of paternal sensory experience is underexplored. We examined the effects of preconception paternal tactile stimulation (PPCTS) by stroking adult male rats three times daily for 14 days before mating with naïve females. Offspring were assessed across infancy, adolescence, and adulthood. During infancy (P10–P15), PPCTS pups were more exploratory, rearing more and exploring novel open-field squares (P11), F(1, 22) = 6.46, p = .018. In adolescence, PPCTS offspring exhibited reduced anxiety-like behavior on the elevated plus maze, F(1, 22) = 4.50, p = .045, with sex × treatment trends showing that females displayed increased rearing and fewer stereotypies. In adulthood, overall locomotion was unchanged, yet open-arm time on the elevated plus maze was reduced, F(1, 24) = 4.45, p = .046. PPCTS offspring also demonstrated enhanced skilled motor behavior in the Whishaw Tray Reaching task, with greater total reach engagement and right-paw lateralization, F(1, 24) = 13.51, p = .001. Cortical thickness analyses revealed region- and hemisphere-specific remodeling, with significant increases in medial orbital, frontal (Fr1), and parietal regions, F(1, 22) = 4.55–19.52, p = .001–.044. These results indicate that paternal tactile experience prior to conception selectively shapes exploratory and anxiety-like behavior, skilled motor strategies, and cortical architecture. The findings reveal an intergenerational epigenetic pathway through which paternal sensory experience influences offspring neurodevelopment, suggesting that the paternal environment could be a target for interventions to optimize brain and behavioral outcomes.