22
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Corticospinal sprouting differs according to spinal injury location and cortical origin in macaque monkeys.

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          The primate corticospinal tract (CST), the major descending pathway mediating voluntary hand movements, comprises nine or more functional subdivisions. The role of subcomponents other than that from primary motor cortex, however, is not well understood. We have previously shown that following a cervical dorsal rhizotomy (Darian-Smith et al., 2013), CST projections originating from primary somatosensory (S1) and motor (M1) cortex responded quite differently to injury. Terminal projections from the S1 (areas 3b/1/2) shrank to <60% of the contralateral side, while M1 CST projections remained robust or expanded (>110%). Here, we asked what happens when a central lesion is added to the equation, to better simulate clinical injury. Monkeys (n = 6) received either a unilateral (1) dorsal root lesion (DRL), (2) or a combined DRL/dorsal column lesion (DRL/DCL), or (3) a DRL/DCL where the DCL was made 4 months following the initial DRL. Electrophysiological recordings were made in S1 4 months postlesion in the first two groups, and 6 weeks after the DCL in the third lesion group, to identify the reorganized region of D1-D3 (thumb, index finger, and middle finger) representation. Anterograde tracers were then injected bilaterally to assess spinal terminal labeling. Remarkably, in all DRL/DCL animals, terminal projections from the S1 and M1 extended bilaterally and caudally well beyond terminal territories in normal animals or following a DRL. These data were highly significant. Extensive sprouting from the S1 CST has not been reported previously, and these data raise important questions about S1 CST involvement in recovery following spinal injury.

          Related collections

          Author and article information

          Journal
          J. Neurosci.
          The Journal of neuroscience : the official journal of the Society for Neuroscience
          1529-2401
          0270-6474
          Sep 10 2014
          : 34
          : 37
          Affiliations
          [1 ] Department of Comparative Medicine, Stanford University School of Medicine, Stanford, California 94305-5342 cdarian@stanford.edu.
          [2 ] Department of Comparative Medicine, Stanford University School of Medicine, Stanford, California 94305-5342.
          Article
          34/37/12267
          10.1523/JNEUROSCI.1593-14.2014
          4160766
          25209269
          a319952b-ed7d-48ef-9464-abfbbc125adb
          Copyright © 2014 the authors 0270-6474/14/3312267-13$15.00/0.
          History

          axonal sprouting,corticospinal pathway,motor cortex,nonhuman primate,somatosensory cortex,spinal cord injury

          Comments

          Comment on this article