News in Physiological Sciences, Vol 1, 15-19, Copyright © 1986 by International Union of Physiological Sciences
Reorganization of the Somatosensory Cerebral CortexAfter Peripheral Damage
R Verley
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.
