Long-term impact of oral gestational PM10 exposure on morris water maze performance and hippocampal gene expression.

Environmental exposure to air pollution, specially to particulate matter (PM) during pregnancy, plays a significant role in increasing the risk of neurodevelopmental disorders such as autism. This study investigated the long-term impact of oral gestational PM exposure (200 µg/kg/day) on memory in aged rats using the Morris Water Maze (MWM). After completing MWM, hippocampal tissue was collected and analyzed for gene expression. Our findings indicate that gestational PM exposure caused no major developmental alterations, aside from slightly poorer performance in the adherence test. No differences were detected in standard MWM manipulations, however, PM-offspring showed reduced latency in the test session, suggesting a possible compulsive-like behavior. Additionally, hippocampal gene expression revealed downregulation of several genes, including NMDA and GABAergic subunits. These effects depended on exposure and sex. The behavioral effects might reflect cognitive inflexibility linked to gene alterations. Further research is needed to clarify these outcomes.