Once upon the 20th century there was a dogma in physiology. It maintained that the highly specialized nervous tissue once developed cannot change but only degenerate. Neurons were thought to be unable to re-specialize – i.e., to multiply, to grow anew and to reconnect. However, during the last decades the doctrine was experimentally disproved and scientific brains were rewired.
Growth of new neurons was observed to occur in rats upon change of sexual environment. Studies of monkeys[i] and of phantom limb[ii] sensation showed that the somatosensory cortex undergoes substantial reorganization after the sensory input is lost. It was found that the visual cortex in congenital blind people is specialized to process tactile information. The unusually high musicality or sense of touch that blind people sometimes develop as a compensation for their absent sense is an example of profound cortical reorganization. Nowadays there is a consensus that the nervous system is adaptable to a certain extent. Fully developed neurons are able to grow, branch and form new synaptic connections. The human brain is able to transform its structure. And it normally does so when receptors are damaged.