The influence of mechanoreceptor structures on regenerating sensory axons after cutaneous nerve transection in the...

After nerve transection, cutaneous type I mechanoreceptors (Haarscheiben or tactile domes) preferentially reappear at old loci, although some do appear at new locations. The mechanism by which this topological specificity is maintained was studied by transecting the femoral cutaneous nerve in cats in which about half of the Haarscheiben were removed by cauterization. Thirteen months after nerve transection, domes were found on uncauterized sites at a rate significantly greater than that expected by chance alone, but on cauterized old dome sites at a rate expected by chance alone. It is concluded the reappearance of type I receptors at old receptor sites following nerve transection is primarily due to intrinsic properties of the receptor sites, rather than to guidance of regenerating axonal sprouts to these sites by the endoneurial matrix of the distal stump of the lesioned nerve.