Alcohol-induced disorders can be prevented by avoiding alcohol use during pregnancy completely. Currently, no medication or treatment can reverse the symptoms of fetal alcohol spectrum disorder. However, with neural stem cell (NSC) transplantation, we can reduce the incidence and severity of this disorder. Evidence suggests that NSCs have the potential to reverse neurogenesis dysfunction observed in FASD. Current studies indicate that memory, cognitive, and behavioral abnormalities were corrected in FASD rat models after NSC transplantation (Poulos et al., 152). According to Poulos et al., “the neurodegeneration observed in FASD has been attributed to ethanol-induced oxidative stress via generation of reactive oxygen species (ROS), and apoptosis of neurons and neuronal progenitors” (152).
We can incorporate transplanted cells into neural circuits. The transplanted stem cells have the ability of nervous system repair by replacing damaged or lost nerve cells. Compared with embryonic stem cells (ESCs), the fate of NSCs is more tightly regulated, but the NSCs have the potential to give rise to all of the major cell types in the CNS and have a lessened chance of tumor formation (Poulos et al., 153).
The first step involves locating the niche location of the stem cells. In this case, the neural stem cells’ niche is the ventricular-subventricular zone of the lateral ventricles of the brain and the subgranular zone of the hippocampus. B cells are derived from radial glia-like NSCs in the adult V-SVZ. These type B cells can differentiate into specific types of neurons in both the olfactory bulb and the striatum (Barresi and Gilbert, p. 153). The dividing B cell gives rise to type C progenitor cells which proliferate and develop into type A neural precursors which are important for the final step of neuronal differentiation. To promote neurogenic growth and repair, an equal balance of cell differentiation and progenitor-generating divisions is required. Notch signaling plays an important role in the maintenance of the pool of B type stem cells. Constant Notch activity in the SVZ niche maintains stem cell quiescence, whereas increasing oscillations of Notch activity versus proneural gene expression progressively promote the maturation of B cell to C cells and then into migrating neural progenitors.
There are other important factors involved in the SVZ niche. EGF blocks notch signaling and one of the prominent players are type C progenitor cells. C cells use epidermal growth factor (EGFR) signaling which upregulates NUMB which in turn inhibits NICD (Notch intracellular domain) (Barresi and Gilbert, p. 156). Thus, EGF signaling promotes the usage of the stem cell pool for neurogenesis by counterbalancing Notch signaling. Further movement toward cell differentiation involves other signals like BMP, which promotes gliogenesis in the SVZ.
Unlike embryonic stem cells, the use of adult stem cells pose no legal problems and can be used for autologous transplantation. Based on the experiments conducted by Aligholi et al., a biopsy (tissue derived from living body) of the SVZ can be safely removed and used in culture for autologous transplantation (82). The final thing to consider is the delivery of the neural stem cells. According to Poulos et al., “intracerebral injection may cause more harm than good due to its highly invasive nature” (154). Therefore, intravenous delivery of NSCs will be conducted.