Splice this: End-to-end annealing demonstrated in neuronal neurofilaments
While popularly publicized neuroscience research focuses on structural and functional connectomes, timing patterns of axonal spikes, neural plasticity, and other areas of inquiry, the intraneuronal environment also receives a great deal of investigative attention.
One example is the study of cytoskeletal polymers called neurofilaments –intermediate filaments of nerve cells that and a major component of the neuronal cytoskeleton believed to provide the axon with structural support. Neurofilaments are transported into axons where they accumulate during development, causing the axons to expand in girth. This is important because the cross-sectional area of an axon influences the rate of propagation of the nerve impulse. The space-filling properties of these polymers are maximized by spoke-like projection domains called side-arms that function to space the polymers apart. Once in the axons these polymers (which are barely 10 nm in diameter) can grow to reach remarkably long lengths – 100,000 nm (0.1 mm) or more – but how they attain such lengths and how their length is regulated is not known. Recently, scientists at The Ohio State University – who previously showed that neurofilaments and vimentin filaments expressed in nonneuronal cell lines can lengthen by joining ends in a process known as end-to-end annealing – demonstrated robust and efficient end-to-end annealing of neurofilaments in nerve cells. In additions, the researchers reported evidence for a neurofilament-severing mechanism.
