Source: Salk Institute for Biological Studies
Date: October 12, 2009
Summary:
LA JOLLA, CA—The cerebral cortex, the largest and most complex component of the brain, is unique to mammals and alone has evolved human specializations. Although at first all stem cells in charge of building the cerebral cortex—the outermost layer of neurons commonly referred to as gray matter—are created equal, soon they irrevocably commit to forming specific cortical regions. But how the stem cells' destiny is determined has remained an open question.
In the Oct. 11 advance online edition of Nature Neuroscience, scientists at the Salk Institute for Biological Studies report that they have identified the first genetic mechanism that determines the regional identity of progenitors tasked with generating the cerebral cortex. Their discovery reveals a critical period during which a LIM homeodomain transcription factor known as Lhx2 decides over the progenitors' regional destiny: Once the window of opportunity closes, their fate is sealed.
