Reorganization of somatosensory cortex subsequent to dorsal column injury: a study of the marmoset and the squirrel monkey
The importance of accurate cortical representation and processing of hand use is clearly appreciated when one considers the behavioral deficits observed after the dorsal columns have been interrupted. Animals experience gross deficits in their ability to accurately guide the affected hand, and addit...
Main Author: | |
---|---|
Other Authors: | |
Format: | Others |
Language: | en |
Published: |
VANDERBILT
2011
|
Subjects: | |
Online Access: | http://etd.library.vanderbilt.edu/available/etd-05312011-104129/ |
id |
ndltd-VANDERBILT-oai-VANDERBILTETD-etd-05312011-104129 |
---|---|
record_format |
oai_dc |
spelling |
ndltd-VANDERBILT-oai-VANDERBILTETD-etd-05312011-1041292013-01-08T17:16:50Z Reorganization of somatosensory cortex subsequent to dorsal column injury: a study of the marmoset and the squirrel monkey Bowes, Charnese Psychology The importance of accurate cortical representation and processing of hand use is clearly appreciated when one considers the behavioral deficits observed after the dorsal columns have been interrupted. Animals experience gross deficits in their ability to accurately guide the affected hand, and additionally, once the item is within its grasp, the animal may keep looking for it due to the loss of tactile sensation. We were able to conclude that somatosensory cortical areas including 3b, 3a, area 1 and possibly area 2 undergo considerable reorganization subsequent to dorsal column injury in the marmoset. We posited that one likely source of this reorganization is the sprouting of collateral axons of primary afferent fibers that remain intact after injury. Whether these postsynaptic nuclei are appropriate targets that go on to make connections with corresponding parts of the body representation in cortex plays a crucial role in determining if amplification of an appropriate signal will occur, or if misperception of the source of input takes place. Prior studies in rats indicate that application of chondroitinase ABC (chABC) to the dorsal column nuclei subsequent to dorsal column pathway damage leads to functional reactive sprouting. We sought to determine how somatosensory cortical organization is affected subsequent to dorsal column pathway damage and chABC application to the cuneate nucleus in squirrel monkeys. In the chABC-treated animals, these recordings showed that cortical territories once activated by deafferented peripheral inputs had become primarily responsive to the D1 afferents that remained intact after the lesion. It will be necessary to not only promote the eventual formation of new and functional synapses but also to provide the guidance necessary for these new circuits to confer behavioral benefits to those affected by SCI. Jon Kaas Troy Hackett Sohee Park Ford Ebner VANDERBILT 2011-08-12 text application/pdf http://etd.library.vanderbilt.edu/available/etd-05312011-104129/ http://etd.library.vanderbilt.edu/available/etd-05312011-104129/ en restricted I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Vanderbilt University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
collection |
NDLTD |
language |
en |
format |
Others
|
sources |
NDLTD |
topic |
Psychology |
spellingShingle |
Psychology Bowes, Charnese Reorganization of somatosensory cortex subsequent to dorsal column injury: a study of the marmoset and the squirrel monkey |
description |
The importance of accurate cortical representation and processing of hand use is clearly appreciated when one considers the behavioral deficits observed after the dorsal columns have been interrupted. Animals experience gross deficits in their ability to accurately guide the affected hand, and additionally, once the item is within its grasp, the animal may keep looking for it due to the loss of tactile sensation.
We were able to conclude that somatosensory cortical areas including 3b, 3a, area 1 and possibly area 2 undergo considerable reorganization subsequent to dorsal column injury in the marmoset.
We posited that one likely source of this reorganization is the sprouting of collateral axons of primary afferent fibers that remain intact after injury. Whether these postsynaptic nuclei are appropriate targets that go on to make connections with corresponding parts of the body representation in cortex plays a crucial role in determining if amplification of an appropriate signal will occur, or if misperception of the source of input takes place.
Prior studies in rats indicate that application of chondroitinase ABC (chABC) to the dorsal column nuclei subsequent to dorsal column pathway damage leads to functional reactive sprouting. We sought to determine how somatosensory cortical organization is affected subsequent to dorsal column pathway damage and chABC application to the cuneate nucleus in squirrel monkeys.
In the chABC-treated animals, these recordings showed that cortical territories once activated by deafferented peripheral inputs had become primarily responsive to the D1 afferents that remained intact after the lesion. It will be necessary to not only promote the eventual formation of new and functional synapses but also to provide the guidance necessary for these new circuits to confer behavioral benefits to those affected by SCI.
|
author2 |
Jon Kaas |
author_facet |
Jon Kaas Bowes, Charnese |
author |
Bowes, Charnese |
author_sort |
Bowes, Charnese |
title |
Reorganization of somatosensory cortex subsequent to dorsal column injury: a study of the marmoset and the squirrel monkey |
title_short |
Reorganization of somatosensory cortex subsequent to dorsal column injury: a study of the marmoset and the squirrel monkey |
title_full |
Reorganization of somatosensory cortex subsequent to dorsal column injury: a study of the marmoset and the squirrel monkey |
title_fullStr |
Reorganization of somatosensory cortex subsequent to dorsal column injury: a study of the marmoset and the squirrel monkey |
title_full_unstemmed |
Reorganization of somatosensory cortex subsequent to dorsal column injury: a study of the marmoset and the squirrel monkey |
title_sort |
reorganization of somatosensory cortex subsequent to dorsal column injury: a study of the marmoset and the squirrel monkey |
publisher |
VANDERBILT |
publishDate |
2011 |
url |
http://etd.library.vanderbilt.edu/available/etd-05312011-104129/ |
work_keys_str_mv |
AT bowescharnese reorganizationofsomatosensorycortexsubsequenttodorsalcolumninjuryastudyofthemarmosetandthesquirrelmonkey |
_version_ |
1716570293766455296 |