The study conducted by Prof. Frank Bradke's team provides indications on brain development and about the causes of diseases of the nervous system. The results have now been published in "Neuron".
Under the microscope, the brain appears as a network of intricate beauty comprising billions of nerve cells (the so-called "neurons") linked together. This network is engaged in a constant process of sharing information. The signals are transmitted from neuron to neuron through fine ramifications of the cell body. However, to acquire this typical structure, young nerve cells have first to go through a shape transformation. "Young neurons have a rather inconspicuous form. They tend to be round and are reminiscent of cherries," comments Frank Bradke, group leader at the DZNE in Bonn. "At this stage, the neuron is much like an island. It is insulated and does not have any direct contact with other cells."
Consequently, nerve cells have to go through a phase of change while they are still in the early stages of their development. To date, little was known about how the cells master this transformation, which is so important for their function. It is essential for the brain's development that its neurons develop contacts to a multitude of other cells. The initial step of this process is that tiny extensions, the so-called "neurites" protrude out of the cell body. The study conducted by the researchers in Bonn and their colleagues sheds light on this process.
A dynamic duo gets its grip on the cell's corset
Investigating mouse brain cells, the neuroscientists were able to identify the three key players involved in the shape change: the cell's cytoskeleton, which consists of specific proteins that give the cell its form and stability, as well as the two proteins named "ADF" and "cofilin." "We were able to show that these two proteins do have a significant impact on cell structure," explains Dr. Kevin Flynn, a postdoc researcher in Bradke's team and first author of the report published in "Neuron". "Much like scissors they cut through the support corset of the cell in the proper location. Neurites can subsequently develop through these gaps."