Immediate and simultaneous sensory reorganization at cortical and subcortical levels of the somatosensory system.

Published

Journal Article

The occurrence of cortical plasticity during adulthood has been demonstrated using many experimental paradigms. Whether this phenomenon is generated exclusively by changes in intrinsic cortical circuitry, or whether it involves concomitant cortical and subcortical reorganization, remains controversial. Here, we addressed this issue by simultaneously recording the extracellular activity of up to 135 neurons in the primary somatosensory cortex, ventral posterior medial nucleus of the thalamus, and trigeminal brainstem complex of adult rats, before and after a reversible sensory deactivation was produced by subcutaneous injections of lidocaine. Following the onset of the deactivation, immediate and simultaneous sensory reorganization was observed at all levels of the somatosensory system. No statistical difference was observed when the overall spatial extent of the cortical (9.1 +/- 1.2 whiskers, mean +/- SE) and the thalamic (6.1 +/- 1.6 whiskers) reorganization was compared. Likewise, no significant difference was found in the percentage of cortical (71.1 +/- 5.2%) and thalamic (66. 4 +/- 10.7%) neurons exhibiting unmasked sensory responses. Although unmasked cortical responses occurred at significantly higher latencies (19.6 +/- 0.3 ms, mean +/- SE) than thalamic responses (13. 1 +/- 0.6 ms), variations in neuronal latency induced by the sensory deafferentation occurred as often in the thalamus as in the cortex. These data clearly demonstrate that peripheral sensory deafferentation triggers a system-wide reorganization, and strongly suggest that the spatiotemporal attributes of cortical plasticity are paralleled by subcortical reorganization.

Full Text

Duke Authors

Cited Authors

  • Faggin, BM; Nguyen, KT; Nicolelis, MA

Published Date

  • August 19, 1997

Published In

Volume / Issue

  • 94 / 17

Start / End Page

  • 9428 - 9433

PubMed ID

  • 9256499

Pubmed Central ID

  • 9256499

International Standard Serial Number (ISSN)

  • 0027-8424

Digital Object Identifier (DOI)

  • 10.1073/pnas.94.17.9428

Language

  • eng

Conference Location

  • United States