Reorganization of the Somatosensory Cerebral CortexAfter Peripheral Damage
If a sensory nerve is sectioned, it is expected that the centrally deprived projection area should be reduced to silence and atrophy. However, in recent years the capacity of the central nervous system for reorganization has received increasing attention. This article concerns elimination of input from the tactile system on the head of rodents, which has two components, the long vibrissae and the common fur. After early destruction of the vibrissae in newborn rats, the deprived cortex unexpectedly was not significantly reduced because substitution occurred. If only the vibrissae were destroyed, small fur hairs substituted for them. If both vibrissae and small hairs on the muzzle were destroyed, fur hairs of other head regions took over. This shows that early deprivation leads to reorganization in the somatosensory cortex that reveals greater than expected plasticity. Thus the principle of specificity of neural connections, a basic principle of neurology, must be reappraised.