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Altered Spatiotemporal Dynamics of Cortical Activation to Tactile Stimuli in Somatosensory Area 3b and Area 1 of Monkeys after Spinal Cord Injury

Reactivation of deafferented cortex plays a key role in mediating the recovery of lost functions, although the precise mechanism is not fully understood. This study simultaneously characterized the dynamic spatiotemporal features of tactile responses in areas 3b and 1 before and 6–8 weeks after part...

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Autores principales: Wu, Ruiqi, Su, Langting, Yang, Pai-Feng, Min Chen, Li
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Society for Neuroscience 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5041163/
https://www.ncbi.nlm.nih.gov/pubmed/27699211
http://dx.doi.org/10.1523/ENEURO.0095-16.2016
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author Wu, Ruiqi
Su, Langting
Yang, Pai-Feng
Min Chen, Li
author_facet Wu, Ruiqi
Su, Langting
Yang, Pai-Feng
Min Chen, Li
author_sort Wu, Ruiqi
collection PubMed
description Reactivation of deafferented cortex plays a key role in mediating the recovery of lost functions, although the precise mechanism is not fully understood. This study simultaneously characterized the dynamic spatiotemporal features of tactile responses in areas 3b and 1 before and 6–8 weeks after partial dorsal column lesion (DCL), and examined how the reactivation relates to the recovery of simple hand use in squirrel monkeys. A combination of high spatiotemporal resolution functional intrinsic optical imaging, microelectrode mapping, behavioral assessment, and tracer histology methods were used. Compared with the normal cortex, we found that the responses of deafferented areas 3b and 1 to 3 s of continuous 8 Hz tactile stimulation of a single digit were significantly weaker and more transient. This finding indicates a loss of response to sustained tactile stimuli. The activation area enlarged for areas 3b and 1 in both directions along digit representation (medial–lateral) and across areas (anterior–posterior). All subjects showed behavioral deficits in a food reaching-grasping-retrieving task within the first 5 weeks after DCL, but recovered at the time when optical images were acquired. Summarily, we showed that these populations of cortical neurons responded to peripheral tactile inputs, albeit in significantly altered manners in each area, several weeks after deafferentation. We propose that compromised ascending driven inputs, impaired lateral inhibition, and local integration of input signals may account for the altered spatiotemporal dynamics of the reactivated areas 3b and 1 cortices. Further investigation with large sample sizes is needed to fully characterize the effects of deafferentation on area 1 activation size.
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spelling pubmed-50411632016-10-03 Altered Spatiotemporal Dynamics of Cortical Activation to Tactile Stimuli in Somatosensory Area 3b and Area 1 of Monkeys after Spinal Cord Injury Wu, Ruiqi Su, Langting Yang, Pai-Feng Min Chen, Li eNeuro New Research Reactivation of deafferented cortex plays a key role in mediating the recovery of lost functions, although the precise mechanism is not fully understood. This study simultaneously characterized the dynamic spatiotemporal features of tactile responses in areas 3b and 1 before and 6–8 weeks after partial dorsal column lesion (DCL), and examined how the reactivation relates to the recovery of simple hand use in squirrel monkeys. A combination of high spatiotemporal resolution functional intrinsic optical imaging, microelectrode mapping, behavioral assessment, and tracer histology methods were used. Compared with the normal cortex, we found that the responses of deafferented areas 3b and 1 to 3 s of continuous 8 Hz tactile stimulation of a single digit were significantly weaker and more transient. This finding indicates a loss of response to sustained tactile stimuli. The activation area enlarged for areas 3b and 1 in both directions along digit representation (medial–lateral) and across areas (anterior–posterior). All subjects showed behavioral deficits in a food reaching-grasping-retrieving task within the first 5 weeks after DCL, but recovered at the time when optical images were acquired. Summarily, we showed that these populations of cortical neurons responded to peripheral tactile inputs, albeit in significantly altered manners in each area, several weeks after deafferentation. We propose that compromised ascending driven inputs, impaired lateral inhibition, and local integration of input signals may account for the altered spatiotemporal dynamics of the reactivated areas 3b and 1 cortices. Further investigation with large sample sizes is needed to fully characterize the effects of deafferentation on area 1 activation size. Society for Neuroscience 2016-09-29 /pmc/articles/PMC5041163/ /pubmed/27699211 http://dx.doi.org/10.1523/ENEURO.0095-16.2016 Text en Copyright © 2016 Wu et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.
spellingShingle New Research
Wu, Ruiqi
Su, Langting
Yang, Pai-Feng
Min Chen, Li
Altered Spatiotemporal Dynamics of Cortical Activation to Tactile Stimuli in Somatosensory Area 3b and Area 1 of Monkeys after Spinal Cord Injury
title Altered Spatiotemporal Dynamics of Cortical Activation to Tactile Stimuli in Somatosensory Area 3b and Area 1 of Monkeys after Spinal Cord Injury
title_full Altered Spatiotemporal Dynamics of Cortical Activation to Tactile Stimuli in Somatosensory Area 3b and Area 1 of Monkeys after Spinal Cord Injury
title_fullStr Altered Spatiotemporal Dynamics of Cortical Activation to Tactile Stimuli in Somatosensory Area 3b and Area 1 of Monkeys after Spinal Cord Injury
title_full_unstemmed Altered Spatiotemporal Dynamics of Cortical Activation to Tactile Stimuli in Somatosensory Area 3b and Area 1 of Monkeys after Spinal Cord Injury
title_short Altered Spatiotemporal Dynamics of Cortical Activation to Tactile Stimuli in Somatosensory Area 3b and Area 1 of Monkeys after Spinal Cord Injury
title_sort altered spatiotemporal dynamics of cortical activation to tactile stimuli in somatosensory area 3b and area 1 of monkeys after spinal cord injury
topic New Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5041163/
https://www.ncbi.nlm.nih.gov/pubmed/27699211
http://dx.doi.org/10.1523/ENEURO.0095-16.2016
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