Neurons are highly efficient in their work, and responsiblefor our interaction with the environment. The way we behave, our memory , themovement of our voluntary muscles are all coordinated by the neurons.
Thus theyare the “basic working units of the nervous system”. A nerve cell recievesinformation by fine branched thread like structure known as the dendrite. This messagein carried by the axon followed by the cell body with the help ofsodium-potassium ion exchange . the signal is finally transmitted to otherneuron by the nerve ending of the first via a chemical known as theneurotransmitter or by ion exchange with the help of gap junction. Neve cellcan transmitt information in seconds of receiving the information during reflexby electrical synapse. However in case of chemical synapse, it takes more time.
Nervecell which send or receive information from the spinal cord or brain are knownto be central nuerons which play a role mainly during reflexes, memory,thought, etc while nerve cells whichpick information from the skin , eye ,etc and deliver information to theskeletal mucles , etc are refered to as peripheral nerve cells. The central nervecells are incapable of regeration primarily because of inavailabity of cells tofill the damaged portion while in the peripheral nerve cells bridges are formedby schwann cells and thus the peripheralnerve cell can heel themselves . However the repair is fully efficient and mayonly occur if the cell body is intact.
Absenceof growth factors which initiate new growth programs and inhibition from neuron supporting cells alsoleads to the incapability of cell division in nerve cells. Nerve cell or nueron are persistent in our body throughoutlife, however if they are damaged or undergo programmed cell death i.eapoptosis, they do not regenerate . Nerve cell are formed only during theembryonic stages. And thus when they are damaged or go under apoptosis whichmaybe due to environmental condition or due to the gene pool , they may lead to several diseases such as parkinson’s andis often fatal.
The diseases caused bythis condition are incurable.