While cultivating hippocampal nerve cells in an external environment, Chinese scientists found that nerve cells would usually produce several short neurites of similar size. Some of them would experience a fast growth in the later development stage, though others could remain the same in terms of size. The fast growing neurites would eventually become axones, and others dendrites. The findings, worked out by a study team made up of scientists from the Shanghai Institute of Life Science, the Graduate School under the Chinese Academy of Sciences, and the Beijing Institute of Life Science, were reported in the January 14 issue of the US journal of Cell.

Further studies also show that the activity of a protein kinase called GSK plays a critical role in regulating the growth of nerve cells. Meanwhile, GSK activity in axones is lower than that in dendrites, though GSK activity could be relatively same in undivided nerve cell neurites. The formation of axones can be blocked, when GSK activity is manipulated to increase. On the contrary, declined GSK activity may lead to the formation of several axones at a single nerve cell, which is very unusual. What makes scientists more surprised is a dendrite can also be turned into an axone, when GSK activity is reduced. Researchers also spotted the upper molecules that can regulate GSK activity. The findings, in addition to unveiling the molecular basis for orderly transmission of brain cell information, also indicate that the application of appropriate drugs can increase the number of axons, in an attempt to help patients repair damaged nerve cells.