Morphological correlates of injury-induced reorganization in primate somatosensory cortex.
BACKGROUND
Topographic reorganization of central maps following peripheral nerve injury has been well characterized. Despite extensive documentation of these physiological changes, the underlying anatomical correlates have yet to be fully explored. In this study, we used Golgi impregnation and light microscopy to assess dendritic morphology following denervation of the glabrous hand surface in adult primates.


RESULTS
After survival durations that permit complete physiologically-defined reorganization, we find a systematic change in the dendritic arborization pattern of both layer II/III pyramidal and layer IV spiny stellate cells in the contralateral hand region of area 3b, compared to unaffected cortical areas. In general, our analyses indicate a progressive expansion of distal regions of the dendritic arbor with no appreciable changes proximally. This pattern of distal dendritic elaboration occurs for both basilar and apical dendrites.


CONCLUSIONS
These observations are consistent with the notion that latent inputs gain expression in reorganized cortex after nerve injury via their influence through contacts with more distally located termination sites.
Churchill
James D
JD
Department of Psychology, Saint Louis University, St. Louis, Missouri 63103, USA. churchj@slu.edu <churchj@slu.edu>
Tharp
Jason A
JA
Wellman
Cara L
CL
Sengelaub
Dale R
DR
Garraghty
Preston E
PE
D000818:Animals; D003712:Dendrites / Q000648:ultrastructure*; D003714:Denervation; D017966:Pyramidal Cells / Q000473:pathology; D012453:Saimiri; D013003:Somatosensory Cortex / Q000166:cytology / Q000293:injuries* / Q000473:pathology*