Nerve Repair and Regeneration also termed Neuroregeneration is associated with the repair or reproduction of the tissues or the cells of the nerves. Procedures as such encourage creation of new axons, synapses, myelin, glia and neurons. The repair and regeneration of nervous tissues vary between the central nervous system and peripheral nervous system on the basis of procedure, speed and extent. When a cell is impaired, it goes through a Wallerian degeneration, dispossessing its myelin sheath.
Studies suggest that every year more than 90,000 people are affected by injuries of the nervous system and 10,000 people are affected by injuries in the spinal cord. Due to increase in neurological injuries, nerve repair and regeneration along with neural tissue engineering is progressing swiftly as a field which is helpful in determining various ways of recovering and treating nerve injuries. The nervous system is separated in two parts; the central nervous system which has the spinal cord and the brain and the peripheral nervous system which has the spinal nerves and the cranial. The peripheral nervous system possesses an underlying ability of regeneration and repairs, whereas the central nervous system is not capable of such regeneration and self-repair. If the central nervous system is damaged, presently there is no treatment available to treat the function of the human nerve. Furthermore, various methods used for reproduction of nerve have been unsuccessful.
Regeneration of central nervous system
The recovery for an injury caused to the central nervous system is not extensive due to limited influence of the extracellular and glial environment. The environment inside the central nervous system permits the repair of the neurons and the myelin after trauma has been caused. Factors of growth are not signified, for example, there is lack of laminis in the extracellular matrix. Glial scars form faster and produce factors that prevent the repair of axons. The potential of growth reduces after an age of the axons themselves due to loss of GAP 43 expression.
Regeneration of peripheral nervous system
Nerve repair and regeneration takes place in the peripheral nervous system to a certain extent. The development of the axonal sprouts is directed by the chemotactic factors that the neurolemmocytes secrete. Any kind of damage to the peripheral nervous systems evokes the movement of the Schwann cells, macrophages and the phagocytes to the lesion in order to clear the tissues that are damaged. After the damage, a swelling occurs in the proximal end and degeneration takes place; however, once the damaged tissues are cleared the axons start to re-grow. If the cell body is undamaged and are in contact with the Schwann cells the proximal axons have the capacity to regenerate. Nurotrophic factors are released by Schwann cells and macrophages that enhance nerve repair and regeneration.