We are born with all of the nerve cells that we ever have and they stay with us until we die. When the brain or spinal cord are injured such from trauma or stroke, some of neurons are directly killed but many neurons die because they commit suicide. Those that die are not replaced with new neurons. Other neurons survive injury but have their axons severed. The axons are long thin extensions of the neurons that are used to communicate over long distances such as from the brain to the spinal cord. When severed, this communication is interrupted causing paralysis and other symptoms. Although axons in the rest of our body can regrow when severed, those in the brain or spinal cord normally do not so that dysfunction is permanent. Exciting recent developments in the search for a cure will be discussed. These include replacing neurons with cloned cells, administering survival molescules to prevent cell suicide and treating the nervous system to make axons regrow.
