NYC Healthcare News

UCSF scientists discover new stem cell in developing human brain

September 18, 2015

The region is a busy hub of cell proliferation. The stem cell undergoes asymmetrical cell division, giving rise to two distinct daughter cells -- one a copy of the original stem cell, the other a transit amplifying cell. The transit amplifying cell undergoes multiple rounds of symmetrical divisions before all of its daughter cells begin the process of differentiating into neurons.

"We are very interested in understanding how these modes of division are regulated," says Kriegstein. "We suspect that faults in cell-cycle regulation account for a variety of developmental brain diseases."

More broadly, he says the team wants to understand how the new stem cells compare to radial glial cells and how the two sets of neurons they produce integrate in the neocortex. "Neurons are probably being generated in both the SVZ and OSVZ at once," he says. "They likely end up in the same layer of the neocortex as they migrate into position and start forming circuits.

"This suggests to us that there may be a mosaic of cell types in the human neocortex, in which there are cells that originate in the traditional zone and cells produced in the newer zone that intermix in the cortex. The complexity of primate neocortex may be significantly increased by the interaction of the evolutionarily-speaking 'younger' neurons with those originating in the more primitive zone."

The massive number of cells within the OSVZ of humans "tells us we have to be careful when modeling human brain diseases in mice," says Kriegstein. "Especially in the neocortex -- the most highly developed part of the brain in primates and humans - there are going to be important differences between rodents and humans."

Source: University of California - San Francisco