Bayly researches the mechanics of brain injury, recently looking into brain deformation due to acceleration of the intact skull. Both have long been aware of a theory posited by their colleague, David Van Essen, Ph.D., the Edison Professor of Neurobiology and head of the School of Medicines Department of Anatomy and Neurobiology. Van Essens hypothesis, published in 1997 in the journal Nature, is a mechanical theory based on tension in the axons (the wiring through which nerve cells communicate). The essence of the hypothesis is that tension in axons is the driving force of folding. Van Essens theory is one of only about a half dozen in the literature concerning the mechanical process of folding. In contrast, much more is known about the genetics of the brain and heart.
Were not sure of the similarities between heart looping and brain folding, Taber said. But there are only a handful of processes that cells use to create shape and form in the embryo. Developing brain and heart cells have the same basic tool set but somehow they integrate them in different ways. Were concerned primarily with the mechanics of how these organs are constructed.
Results so far are only preliminary. Post-doctoral researcher Gang Xu has obtained unexpected data from adult mouse brains in studies performed primarily to demonstrate feasibility of their approach.
Weve observed measurable, sustained tension in the axons, Bayly said. This is significant, because its what David Van Essens theory predicts is necessary for folding.
They are now doing MRI research on newborn ferrets. The ferret is the smallest mammal that has a folded brain, and unlike humans, folding occurs after the animal is born.
Washington University post doctoral in biomedical engineering researcher Gang Xu gave a presentation on the research at the Biomedical Engineering Society Annual Meeting, held Sept. 27-29 in Los Angel
|Contact: Tony Fitzpatrick|
Washington University in St. Louis