Revival of nerves
damage to the brain or spinal cord due to severe injuries has become more frequent nowadays. So, researchers are constantly trying to develop therapies to deal with trauma of this nature. Much interest has been directed at the possibility that neuronal pathways, which do not serve a particular function might spontaneously take over another function after an injury. Neeraj Jain and his colleagues at the Vanderbilt University, usa , say that the nervous system may work on the same principles on which an electric system works. When a wire leading to a particular bulb snaps, the rest of the circuits can be partially rewired so as to compensate for the break (Nature , Vol 386, No 6624).
The researchers carried out a study on monkeys to confirm the claim that such developments can take place after an injury. Their aim was to investigate that damage to the afferent (incoming) nerve bundles in the dorsal (meaning back of head) column of the spinal cord could be followed by recovery in perceiving sensory inputs. The dorsal column is situated near the region of the neck. The area of the brain that is stimulated by these neurones is called primary somatasensory cortex. It receives signals from the hand on the opposite or contralateral side of the body.
Jain and his colleagues cut the relevant spinal afferents and found that stimulation of the contralateral hand did not cause any stimulation in the