Altered social proximity in adult mice following prenatal stress Exposure: An exploratory link to cortical neurogenesis.

Prenatal stress has been implicated in the etiology of neurodevelopmental disorders, yet its impact on cortical morphogenesis and long-term social behavior remains insufficiently characterized. This study aimed to evaluate the effects of prenatal restraint stress on prenatal neurogenesis and social behavior in adult offspring using behavioral and histological approaches. Pregnant mice were subjected to restraint stress (0.5 or 2 h daily from embryonic day (E) 10.5 to 14.5). Histological analysis at E15.5 revealed reduced neurogenesis and intermediate zone formation. Behavioral assessments included social interaction tests and multi-individual proximity tracking using the Multiple Animal Positioning System (MAPS). Offspring exposed to 2 h prenatal stress displayed diminished novelty preference, increased social proximity, and exhibited altered behavioral responses to postnatal stressors. Notably, stress-exposed embryos exhibited reduced neuronal differentiation without gross cortical malformations. These findings suggest that prenatal stress alters cortical neurogenesis and contributes to persistent abnormalities in social behavior. The data provide exploratory evidence that disruption of inhibitory neuron development may underpin altered circuit formation and behavioral sensitivity.