Striatal synaptic changes and behavior in adult mouse upon prenatal exposure to valproic acid.

Scientists studied mice exposed to a medication called valproic acid before birth, which increases autism risk in humans. Adult mice showed autism-like behaviors including repetitive actions and difficulty adapting to new situations, though they were better at learning motor skills. Brain examination revealed changes in proteins important for brain cell connections, particularly in areas controlling movement and habits. This research helps explain how early environmental exposures might affect brain development and lead to autism-related behaviors.

This preclinical study investigated autism-like behaviors and brain changes in adult mice exposed to valproic acid (VPA) during prenatal development. VPA exposure is an established environmental risk factor for autism spectrum disorder. The research examined behavioral changes and synaptic protein levels in brain regions associated with repetitive behaviors and learning. Adult mice prenatally exposed to VPA showed altered repetitive behaviors, improved motor skill learning, but cognitive deficits in spatial learning tasks.

These behavioral changes were associated with decreased levels of key synaptic proteins (Nlgn-1 and PSD-95) in the striatum, suggesting reduced excitatory synaptic function in brain circuits involved in habit formation and behavioral flexibility.

While this preclinical research cannot directly inform clinical practice, it advances understanding of how prenatal environmental exposures may contribute to autism development through specific brain mechanisms. The findings support the importance of avoiding VPA during pregnancy when possible and may guide future research into therapeutic targets for repetitive behaviors.

This is an animal study with unclear sample size, limiting direct translation to humans. The abstract doesn't specify the timing or dose of VPA exposure, statistical analyses used, or effect sizes. Long-term outcomes and potential interventions were not explored.

Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders characterized by persistent deficits in social communication and social interaction. Altered synaptogenesis and aberrant connectivity responsible for social behavior and communication have been reported in autism pathogenesis. Autism has a strong genetic and heritable component; however, environmental factors including toxins, pesticides, infection and in utero exposure to drugs such as VPA have also been implicated in ASD. Administration of VPA during pregnancy has been used as a rodent model to study pathophysiological mechanisms involved in ASD, and in this study, we used the mouse model of prenatal exposure to VPA to assess the effects on striatal and dorsal hippocampus function in adult mice.

Alterations in repetitive behaviors and shift habits were observed in mice prenatally exposed to VPA. In particular, such mice presented a better performance in learned motor skills and cognitive deficits in Y-maze learning frequently associated with striatal and hippocampal function. These behavioral changes were associated with a decreased level of proteins involved in the formation and maintenance of excitatory synapses, such as Nlgn-1 and PSD-95. In conclusion, motor skill abilities, repetitive behaviors, and impaired flexibility to shift habits are associated with reduced striatal excitatory synaptic function in the adult mouse prenatally exposed to VPA.