Smith, CC, Paton, JFR, Chakrabarty, S orcid.org/0000-0002-4389-8290 et al. (1 more author) (2017) Descending systems direct development of key spinal motor circuits. Journal of Neuroscience, 37 (26). pp. 6372-6387. ISSN 0270-6474
Abstract
The formation of mature spinal motor circuits is dependent on both activity dependent and independent mechanisms during postnatal development. During this time, reorganisation and refinement of spinal sensorimotor circuits occurs as supraspinal projections are integrated. However, specific features of postnatal spinal circuit development remain poorly understood. This study provides the first detailed characterisation of rat spinal sensorimotor circuit development in the presence and absence of descending systems. We show that development of proprioceptive afferent (PA) input to motoneurones (MN) and Renshaw cells (RC) is disrupted by thoracic spinal cord transection (TX) at postnatal day 5 (PN5). PN5TX also lead to malformation of GABApre neuron axo-axonic contacts on Ia afferents and the recurrent inhibitory circuit between MN and RC. Using a novel in situ perfused preparation for studying motor control, we show that malformation of these spinal circuits leads to hyperexcitability of the monosynaptic reflex. Our results demonstrate that removing descending input severely disrupts development of spinal circuits and identifies key mechanisms contributing to motor dysfunction in conditions such as cerebral palsy and spinal cord injury.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 the authors. This is an author produced version of a paper published in Journal of Neuroscience. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | GABApre neurons; plasticity; proprioceptive afferents; Renshaw cells; sensorimotor; spinal cord |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Biomedical Sciences (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 01 Aug 2017 10:45 |
Last Modified: | 19 Apr 2018 10:03 |
Status: | Published |
Publisher: | Society for Neuroscience |
Identification Number: | 10.1523/JNEUROSCI.0149-17.2017 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:119653 |