Mechanisms underlying neuro-inflammation and neurodevelopmental toxicity in the mouse neocortex following prenatal exposure to ethanol

Fetal alcohol spectrum disorders (FASD) constitute a wide range of disorders that arise from prenatal exposure to ethanol (EtOH). However, detailed reports regarding the adverse effects of prenatal EtOH exposure on neocortical morphology and its underlying pathogenic mechanisms are limited. In the present study, we aimed to characterize the anatomical abnormalities of neocortical development and their correlation with microglial properties and neuro-inflammation in a mouse model of FASD. We evaluated the development and maturation of the neocortex in ICR mice prenatally exposed to 25% (w/v) EtOH using histological and molecular analyses. Reduced proliferation and excessive cell death were observed in the dorsal telencephalon. Abnormal neuronal distribution, layer formation, and dopaminergic neuronal projections were observed in the neocortex. Disruption of microglial differentiation (M1/M2 microglial ratio) and abnormal expression of pro-inflammatory and neurotrophic factors were induced, and these abnormalities were ameliorated by co-treatment with an anti-inflammatory drug (pioglitazone). FASD model mice displayed histological abnormalities, microglial abnormalities, and neuro-inflammation in both the embryonic and newborn stages. Thus, anti-inflammatory therapeutics may provide a novel preventive approach for the treatment of FASD.