Prenatal Hypoxia Leads to Impaired Formation of Nervous Tissue in the Entorhinal Area of the Cerebral Cortex in Rats

Maternal Hypoxia Increases the Excitability of Neurons in the Entorhinal Cortex and Dorsal Hippocampus of Rat Offspring

“…However, in our previous works focused on the study of structural abnormalities in the parietal cortex ( Vasil’ev et al, 2008 ), EC ( Vasilev et al, 2021 ), and hippocampus ( Zhuravin et al, 2009 ), we analyzed Nissl stained brain slices. The data concerning the distribution of the NeuN neuronal marker and glia cell markers in the EC and CA1 of the hippocampus of hypoxic rats presented in this study suggest that prenatal hypoxia leads to the death of neurons in EC but not to the activation of glial cells.…”

“…It can also be concluded that the EC is more vulnerable to the destructive action of hypoxia on E14 than the CA1 area of the hippocampus. Such a difference in vulnerability might be predictable considering that hypoxia on E14 specifically disturbs radial neuroblast migration in cortical areas, including the entorhinal cortex ( Vasilev et al, 2016 , 2021 ). However, it does not directly affect the dorsal hippocampus that emerges later in embryogenesis ( Rice and Barone, 2000 ).…”

“…The most probable cause of the hippocampus vulnerabilities might be based on the intimate connection between the hippocampus and brain cortical areas (e.g., prefrontal cortex, entorhinal cortex). The hypoxia on E14 disrupts the formation of the entorhinal cortex ( Vasilev et al, 2021 ), especially the projection neurons forming the temporoammonic pathway directed to the CA1 area. We showed earlier a decrease in the number of synapses formed by synaptopodin-positive labile dendritic spines in the CA1 area of the hippocampus of P20–30 rats subjected to prenatal hypoxia on E14 ( Zhuravin et al, 2019 ).…”