Neuroregeneration

Not to be confused with Neurogenesis.

Neuroregeneration involves the regrowth or repair of nervous tissues, cells or cell products. Neuroregenerative mechanisms may include generation of new neurons, glia, axons, myelin, or synapses. Neuroregeneration differs between the peripheral nervous system (PNS) and the central nervous system (CNS) by the functional mechanisms involved, especially in the extent and speed of repair. When an axon is damaged, the distal segment undergoes Wallerian degeneration, losing its myelin sheath. The proximal segment can either die by apoptosis or undergo the chromatolytic reaction, which is an attempt at repair. In the CNS, synaptic stripping occurs as glial foot processes invade the dead synapse.[1]

Nervous system injuries affect over 90,000 people every year.[2] Spinal cord injuries alone affect an estimated 10,000 people each year.[3] As a result of this high incidence of neurological injuries, nerve regeneration and repair, a subfield of neural tissue engineering, is becoming a rapidly growing field dedicated to the discovery of new ways to recover nerve functionality after injury.

The nervous system is divided by neurologists into two parts: the central nervous system (which consists of the brain and spinal cord) and the peripheral nervous system (which consists of cranial and spinal nerves along with their associated ganglia). While the peripheral nervous system has an intrinsic ability for repair and regeneration, the central nervous system is, for the most part, incapable of self-repair and regeneration. There is currently no treatment for recovering human nerve-function after injury to the central nervous system.[4] Multiple attempts at nerve re-growth across the PNS-CNS transition have not been successful.[4] There is simply not enough knowledge about regeneration in the central nervous system. In addition, although the peripheral nervous system has the capability for regeneration, much research still needs to be done to optimize the environment for maximum regrowth potential. Neuroregeneration is important clinically, as it is part of the pathogenesis of many diseases, including multiple sclerosis.

  1. ^ Kandel ER, Schwartz JH, Jessell TM (2003). "Chapter 55: The formation and regeneration of synapses". Principles of neural Science (fourth ed.). Cambridge: McGraw Hill. ISBN 978-0-8385-7701-1.
  2. ^ Stabenfeldt SE, García AJ, LaPlaca MC (June 2006). "Thermoreversible laminin-functionalized hydrogel for neural tissue engineering". Journal of Biomedical Materials Research Part A. 77 (4): 718–25. doi:10.1002/jbm.a.30638. PMID 16555267.
  3. ^ Prang P, Müller R, Eljaouhari A, Heckmann K, Kunz W, Weber T, Faber C, Vroemen M, Bogdahn U, Weidner N (July 2006). "The promotion of oriented axonal regrowth in the injured spinal cord by alginate-based anisotropic capillary hydrogels". Biomaterials. 27 (19): 3560–9. doi:10.1016/j.biomaterials.2006.01.053. PMID 16500703.
  4. ^ a b Recknor JB, Mallapragada SK (2006). "Nerve Regeneration: Tissue Engineering Strategies". In Bronzino JD (ed.). The biomedical engineering handbook (third ed.). Boca Raton, Fla.: CRC Taylor & Francis. ISBN 978-0-8493-2123-8.