Have you ever felt like you brain was acting slow… you were just not thinking clearly. You may have pondered, “I wish my brain would work better” or, “I wish I had more brain cells”? Well, turns out, at one point you did have more brain cells… they just died off.
During the early stages of development, excess brain cells (neurons) are formed. However over a mere ~24 hour period, your chances for Harvard or Oxford may be wiped away as about half of the neurons disappear in certain parts of your nervous system. It was previously believed that the cells’ competition for limited growth factors was a random process. All early cells were the same and had an equal chance of binding the growth factors, leading to either life or death. However newer research in Nature Communications may prove differently.
A Swedish group at the Karolinska Institute published a paper showing a natural selection process, almost Darwinian, in which only the best and most successful cells survive. All of the baby neurons have receptors ready to bind local growth factors, however only some have distinct molecular features making them more likely to respond. The ones unlikely to make good connections within the nervous system seem to die off quickly.
This finding may be crucial in understanding investigational stem cells transplants for nervous system diseases, like Parkinson’s disease. In most studies, stem cells are implanted in the brain, but quickly die or turn into scar tissue. (This is what occurred in my research using stem cells for Parkinson’s during my training.) It is possible the transplants could be more successful if the most “fit” cells were weeded out before the transplant.
I guess this is just another example of the top 1% of 1% having unfair advantage.