Principal mechanism of the cortical reorganization following loss of receptors
The removal of receptors deactivates their cortical sensory area as well as those regions of the brain to which it transmits information. The neighbouring active cortical sensory areas tend to involve the deactivated one in their activity. Part of their sensory input is redirected towards the deactivated area. Their neurons form a new connection with its neurons. The cortical reorganization following the loss of receptors eventually rewires, reactivates and reutilizes the deactivated sensory area and replaces its sensory input. The capacity of the brain to process the redirected input increases.
The cortical reorganization following the loss of receptors consists in reutilization of their sensory area by other somatosensory pathways. The process is shown at the three-component scheme as an interaction of the cortical sensory areas of three adjacent somatosensory pathways. Each of them and its information is presented with a specific colour. The first part of the scheme shows the normal functioning of the three somatosensory pathways that provides for normal perception. The second part of the scheme shows deactivation of the middle somatosensory pathway due to loss of its receptors which is presented by discoloration and leads to deficiency of perception. The third part of the scheme shows reutilization of the middle pathway by redirection of the nervous signal of the intact somatosensory pathways through it. The loss of receptors deactivates their sensory area (II) and triggers a cortical reorganization that reutilizes it and increases the potential of the brain to manage the information of the neighbouring areas (III).
The cortical reorganization compensates for the lost sensitivity by refining the interpretation of other sensory inputs. The lost sensitivity of a scar, for instance, is compensated by increased sensitivity to signals coming from adjacent regions of the skin and the informational vacuum in perception tends to be filled with their inputs. With the advance of the cortical reorganization the awareness of the existence of the scar disappears. The cortical reorganization virtually heals the scars. It adapts the brain to the alteration of the body and masks the loss of sensitivity. The cortical reorganization adjusts the brain to the shortage of information so it increases subjectivity of perception.