Combined effects of prenatal inhibition of vasculogenesis and neurogenesis on rat brain development

Malformations of cortical development (MCD) are one of the most common causes of neurological disabilities including autism and epilepsy. To disrupt cortical formation, methylazoxymethanol (MAM) or thalidomide (THAL) has been used to affect neurogenesis or vasculogenesis. Although previous models of MCD have been useful, these models primarily attack a single aspect of cortical development. We hypothesized that simultaneous prenatal exposure to MAM or THAL will lead to the development of a novel and specific type of brain maldevelopment. Rats were prenatally exposed to MAM and THAL. At early postnatal days, brains displayed abnormal ventricular size and hemispheric asymmetry due to altered brain water homeostasis. The postnatal brain was also characterized by gliosis in regions of focal leakage of the blood brain barrier. These morphological abnormalities gradually disappeared at adult stages. Although the adult MAM-THAL rats showed normal cortical morphology, abnormal hippocampal connectivity and mossy fiber sprouting persisted well into adulthood.