In laying down the neural circuitry of the developing brain, billions of neurons must first migrate to their correct destinations and then form complex synaptic connections with their new neighbors.
When the process goes awry, neurodevelopmental disorders such as mental retardation, dyslexia or autism may result.
Scientists led by Franck Polleux, Ph.D., associate professor of pharmacology at the University of North Carolina at Chapel Hill School of Medicine have now discovered that establishing the neural wiring necessary to function normally depends on the ability of neurons to make finger-like projections of their membrane called filopodia.
The finding, published as the cover story of the Sept. 4 issue of the journal Cell, indicates that the current notion regarding how cells change shape, migrate or differentiate needs to be revisited.
According to Polleaux, scientists have thought that the only way for a cell to morph and move is through the action of the cytoskeleton or the scaffold inside the cell, pushing membrane forward or sucking it in.
But Polleux’s study shows that the brain protein srGAP2 can also impose cell shape by directly bending membranes, forming filopodia as a mean to control the migration and branching of neurons during brain development.
Les Lang (Video produced by Chris Carmichael)