Anxiety and abnormal hippocampal neurogenesis in adult rat offspring after high-speed train indoor pressure exposure during early pregnancy

This study investigates the effects of prenatal stress induced by transient pressure fluctuations. To model this, pregnant rats were exposed to high-speed train indoor pressure (HIP) during the early stage of gestation. To assess the effects of these prenatal stressors, behavioral tests in adult offspring were conducted, focusing on both anxiety-like behaviors and emotional regulation, while hippocampus development was analyzed using histological and molecular techniques. Behavioral assessments revealed significant anxiety-like behaviors in the experimental group, indicating heightened anxiety. Further hippocampus analysis using histological techniques demonstrated a decrease in neuronal density and synaptic plasticity, particularly in the CA1 and dentate gyrus (DG) regions. Molecular analysis revealed down-regulation of glucocorticoid receptors (GR), aberrant activation of the PLCγ1 signaling pathway, and up-regulation of NMDAR. These molecular alterations were particularly evident in female offspring. In summary, these findings suggest that maternal exposure to transient pressure fluctuations during early pregnancy disrupts hippocampal development, leading to long-term emotional regulation deficits and anxiety-like behaviors in offspring.