Neurospheres as a Model for Developmental Neurotoxicity Testing

Developmental neurotoxicity (DNT) of environmental chemicals is a serious threat to human health. So far, DNT testing is performed in animals. Such in vivo testing is time-consuming, expensive, and uses large numbers of animals. Moreover, species differences (rat–human) bear the problem of extrapolation. Thus, alternative tests are needed to provide faster and cheaper methods for DNT testing. Neurospheres are free-floating three-dimensional structures consisting of neural progenitor cells. Within the “neurosphere assay,” basal processes of brain development, such as proliferation, migration, differentiation, and apoptosis, are mimicked. These processes can be disturbed by chemicals, and thus predict DNT. Therefore, we consider this cell system as a promising tool for DNT in vitro testing. The methods to determine the effects of chemicals on DNT-specific endpoints are described in this chapter.