What is "neurosphere"

n. (context embryology neurology English) A free-floating structure generated ''in vitro'' by neural stem cells

A neurosphere is a culture system composed of free-floating clusters of neural stem cells. Neurospheres provide a method to investigate neural precursor cells in vitro. Putative neural stem cells are suspended in a medium lacking adherent substrates but containing necessary growth factors, such as epidermal growth factor and fibroblast growth factor. This allows the neural stem cells to form into the characteristic 3-D clusters. However, neurospheres are not identical to stem cells; rather, they only contain a small percent of neural stem cells.

The predominant use of the neurosphere is in the neurosphere assay. However, in vitro and in vivo environments have shown to have different inductive effects on precursor cells. The creation of the neurosphere assay is highly sensitive; it is still unclear as to the exact differing effects that environment produces, relative to the in vivo environment.