The brain is, by definition, plastic: malleable, moldable throughout life thanks to the fundamental property of neurons to rearrange themselves according to their own activity.
This plasticity, synonymous with learning potential, is greatest early in life, and diminishes over the years — making us increasingly better and more specialized in what we do.
On the one hand, therefore, loss of plasticity is desirable. It's the one that "fixes" your mother tongue, the circuits you use to move your eyes together to form one image, the others that allow you to ride a bike without ever unlearning it. Different systems mature at different ages, but several are "fixed" in place as astrocytes form a sugary cloak around neurons, which, like a varnish, protects the work from future modification.
The cover is the perineuronal mesh, a subject of study by neuroscientists who suspect that while it is useful in fixing learning, on the other hand it is one of the major impediments to reorganizing the nervous system in the event of a disaster — for example, when There is a spinal cord injury from falling, car accident or gunshot wound.
The perineuronal mesh is made up of proteoglycans, large, cup-washing brush-shaped molecules whose central axis (the wire) is a protein, and the brush bristles are sugars attached to the protein. Several proteoglycans, in turn, bind to proteins present between cells, such as cup-cleaning brushes hanging from a clothesline — and thus each neuron has its central body properly "hooded" and protected by a mesh of clotheslines.
With such protection, even if a neuron disrupted by an injury would want so badly, it could grow back and reconnect to its hooded target.
Researchers like Jerry Silver of Case Western Reserve University in Cleveland, then decided to try removing the cover to promote regeneration. Silver and his students have recently demonstrated that with injections of enzyme that eats the proteoglycan coat long enough, mice with complete damage to one half of the spinal cord have sufficient regeneration of the remaining fibers to allow them to walk again.
Of course, deciding to inject enzymes that destroy proteoglycans into the body is not trivial; These, after all, are also the essence of the body's cartilage. But such injections may prove to be the best way to literally pave the way for regeneration of the nervous system.
. (tagsToTranslate) brain (t) neuroscience (t) sheet