Mouse model of prenatal valproic acid exposure: Effects on cortical morphogenesis and behavioral outcomes across environmental conditions.

Researchers gave pregnant mice valproic acid (an epilepsy medication) and studied the baby mice's brain development and behaviour. The medication caused brain changes and autism-like behaviours, but the severity depended on whether mice lived alone or in groups. Mice living alone showed more problems with movement and anxiety, while all mice had some social difficulties regardless of living situation. This suggests that both prenatal medication exposure and later environment can affect autism-like behaviours.

This mouse study examined how prenatal valproic acid (VPA) exposure affects brain development and behaviour, with particular attention to environmental housing conditions. Pregnant mice received VPA on embryonic day 12, and offspring were assessed for brain changes and behavioural outcomes. Results showed VPA exposure increased cell proliferation and caused microglial abnormalities in the developing brain. Behavioural effects varied by housing environment: single-housed mice showed reduced locomotor activity, increased anxiety, and social interaction problems, while group-housed mice showed fewer activity changes but still had social difficulties.

The study suggests environmental factors can modify how prenatal drug exposure affects autism-like behaviours in animal models.

Findings suggest prenatal VPA exposure affects brain development and behaviour in ways that vary with environmental conditions. This supports considering both biological and environmental factors in understanding autism development, though human studies needed to confirm relevance.

Single dose and timing of VPA exposure may not reflect human exposure patterns. Sample size not reported. Animal model findings may not directly translate to human autism. Limited assessment of long-term outcomes.

Autism spectrum disorder is a developmental disability characterized by impaired social communication and repetitive behaviors, and environmental and genetic factors are involved in its onset. The use of the antiepileptic drug valproic acid (VPA) during pregnancy is associated with neural tube defects and developmental disorders in the fetus. In this study, we aimed to identify abnormalities in cortical morphogenesis owing to prenatal VPA exposure and to elucidate the abnormalities in brain function associated with these abnormalities, particularly by comparing multiple and single environments. Pregnant mice were administered a single dose of 400 mg/kg/day of VPA on embryonic day 12, and the morphogenesis and behavioral characteristics of the fetal and newborn mouse brains were analyzed.

Prenatal VPA exposure caused an increase in cell proliferation and morphological abnormalities in microglia. In the single-housing environment, a decrease in spontaneous locomotor activity and psychomotor activity, and an increase in anxiety-like behavior and abnormal social interactions, were observed. In the multiple-housing environment, no effect on spontaneous activity was detected, however, an effect on social interactions and social proximity was observed. These findings provide valuable insights into the effects of environmental factors during the fetal period on the risk of developmental disorders.

Moreover, they indicate that developmental disorder-like behavior is also affected by the environment.