Neuroscientists have never fully understood how new adult brain cells are able to traverse the relatively long distances they need to cover in order to reach their final locations within the brain. LiveScience.com is reporting today that a recent study of mouse brains co-authored by researchers at the University of California, San Francisco sheds some light on the important role that cilia play in brain cell migration.
New adult brain cells are born within the cerebrospinal fluid that occupies the lateral ventricles of the brain. The ventricle walls are lined with cilia, tiny hair-like extensions of the plasma membrane that oscillate and stir up the cranial fluid creating a molecular concentration differential. The new neurons use this concentration gradient as a guide to their final destination.
While studying adult mouse brains, the researchers found that the neurons they were observing eventually made their way to the olfactory bulb, the structure in the forebrain of mammals responsible for the perception of odors. While the scientists do not know why the cells travel to the olfactory bulb, they do believe that the behavior is probably similar in humans. They also haven’t ruled out the possibility that neurons migrate to other structures as well, based on the previous knowledge that glial cells, non-neuronal cells that provide support and aid in signal transmission, migrate within the nervous system.
The study appears in the January 12th issue of the online version of the journal Science.