Researchers have identified a distinct group of early-stage neural stem cells, called neural rosette cells, that can form more types of neural cells than typical neural stem cells, reports a study published today (January 14) in Genes & Development.

As neural stem cells develop from embryonic stem cells, they form a radial pattern of epithelial cells, called rosettes. Scientists had seen the morphology before, but "nobody understood rosette cells," Lorenz Studer at Memorial Sloan-Kettering Cancer Center, the lead investigator on the study, told The Scientist.

Studer and his colleagues isolated neural rosette cells and profiled them genetically, finding an expression pattern distinct from neural stem cells. But the most exciting quality of rosette cells is that it appears they can develop into any type of neural cell, representing a population that behaves more like true stem cells. Whereas neural stem cells in culture typically only differentiate into GABA-ergic or glutamatergic neurons, Studer's team enticed neural rosette cells to become forebrain, midbrain, and spinal cord neurons.

"This work supports the idea that, at least in early development, there are populations much more broad in their differentiation potential," Jeffrey Macklis at Harvard Medical School, who was not involved in the study, told The Scientist.

Studer is convinced these neural rosette cells can become any type of neural cell, but he has yet to prove it. "We haven't shown them all, but we can make the extreme [neural] types, the most anterior and posterior," Studer said. The reason these cells had not been characterized before, he said, was because neural stem cells are usually isolated from a later stage.

Macklis said he would be interested to see the results of in vivo experiments using chimeric animals with traceable neural rosette cells. "Those data would further elucidate whether these cells are really at a very early stage of nervous system lineage restriction" or if there are neural stem cells at an even earlier stage.