Comparing the effect of skilled forelimb rehabilitative training after unilateral cervical contusion and dorsal quadrant spinal cord injury in female Lewis rats

DOI:10.34945/F5DS3C

DATASET CITATION

Fouad K., Lucas Osma A. M., Vavrek R., Fenrich K. K., Bennett, D. (2022) Comparing the effect of skilled forelimb rehabilitative training after unilateral cervical contusion and dorsal quadrant spinal cord injury in female Lewis rats. ODC-SCI:747 http://doi.org/10.34945/F5DS3C

ABSTRACT

STUDY PURPOSE: Moderate cervical spinal cord injury (SCI) models target spinal tracts involved in skilled reaching and grasping. Contusion SCIs are often considered the most clinically relevant injuries. They involve lateral gray matter damage and it is unknown whether rats with a cervical contusion can be trained in skilled reaching and grasping task (single pellet reaching, grasping and retrieval; SPRGR). Here we compare the impact of injury size on recovery in a SPRGR task, in rats with cervical unilateral contusion injuries (UCs) with a dorsolateral quadrant transection (DLQ).

DATA COLLECTED: Age matched adult female Lewis rats (n = 26 UC and n = 13 DLQ; 200–230 g; Charles River, Canada), were trained to retrieve food pellets. Untrained controls were placed in the training enclosures and received pellets on the floor of the enclosure where they could be licked rather than grasped. Following pre-training 5 days/week, for 6 weeks and baseline testing of the preferred paw all rats received a cervical SCI between C4-5 on the side of the preferred paw For DLQ injuries a dorsolateral quadrant SCI was performed using custom made blades. UC animals received a C5 unilateral contusion, with the tip of the impactor device (2.5 mm diameter, IH-0400 Impactor, Precision Systems and Instrumentation) over the spinal cord at 1.25 mm lateral of the midline. Impact force was set to 125 Kdyn with no dwell-time. Starting 1 week post-injury, rats were divided into untrained and trained groups based on day 4 forelimb injury severity score. A blinded researcher evaluated performance in the trained task at 1, 3, and 5 weeks of training from 10 min videos. After the final day of testing, rats were euthanized, perfused, and spinal cord tissue was harvested. Cervical spinal cords including the lesion site were cut at 25 microns and processed with Cresyl violet and Neurotrace staining. Cresyl violet-stained spinal cord sections were assessed for lesion size using light and fluorescence microscopy. Tissues sections (25 µm) were imaged and quantified, every 200 µm from 2.4 mm rostral to 2.4 mm caudal of injury epicenter, to assess tissue damage. Using ImageJ the corticospinal tract (CST) and the rubrospinal tract (RST) damage was quantified based on the reported projection sites.

CONCLUSIONS: Both UCs and DLQs cause considerable damage to spinal tracts that are important for skilled forelimb movements. UCs lead to significantly more ventral and dorsal grey matter damage, as well as more ventral white matter damage than DLQs. UCs result in severe motor impairments in the reaching task soon after injury, yet there is some spontaneous recovery over time and training is effective in promoting additional recovery in the task. We conclude that the unilateral C5 contusion model is a suitableto evaluate the efficacy of training and other plasticity promoting treatments in rats.

KEYWORDS

Spinal cord injury, Unilateral contusion, Dorsolateral quadrant transection, Grey matter loss, Corticospinal tract, Rubrospinal tract, Single pellet reaching, Forelimb motor task, Skilled motor task, Functional recovery, Rehabilitative training, Neuroplasticity

PROVENANCE / ORIGINATING PUBLICATIONS

• Schmidt E, Raposo P, Vavrek R, Fouad K. Inducing inflammation following subacute spinal cord injury in female rats: A double-edged sword to promote motor recovery. Brain Behav Immun. 2021 Mar;93:55-65. doi: 10.1016/j.bbi.2020.12.013. Epub 2020 Dec 21. PMID: 33358981.

• Lucas-Osma AM, Schmidt EKA, Vavrek R, Bennett DJ, Fouad K, Fenrich KK. Rehabilitative training improves skilled forelimb motor function after cervical unilateral contusion spinal cord injury in rats. Behav Brain Res. 2022 Mar 26;422:113731. doi: 10.1016/j.bbr.2021.113731. Epub 2021 Dec 31. PMID: 34979221.

RELEVANT LINKS

NOTES

DATASET INFO

Contact: Fenrich Keith (fenrich@ualberta.ca)

Lab: Keith K Fenrich

ODC-SCI Accession:747

Records in Dataset: 42

Fields per Record: 106

Last updated: 2022-06-10 (See changelog)

Date published: 2022-06-10

Downloads: 35

Files: 2

LICENSE

Creative Commons Attribution License (CC-BY 4.0)

FUNDING AND ACKNOWLEDGEMENTS

Canadian Institute of Health Research (PS 153179) and Craig H. Neilsen Foundation (NPRG 542589) KF

CONTRIBUTORS

Fouad, Karim [ORCID:0000-0001-6350-5223]

Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada; Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Canada. Electronic address: karim.fouad@ualberta.ca.

Lucas Osma, Ana M. [ORCID:0000-0002-6792-9856]

Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada b Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada

Schmidt, Emma [ORCID:0000-0001-9803-6391]

Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada.

Raposo, Pamela [ORCID:0000-0001-6350-5223]

Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Canada.

Vavrek, Romana [ORCID:0000-0003-1966-1258]

Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Canada.

Fenrich, Keith K. [ORCID:0000-0003-4360-064X]]

Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada b Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada

Bennett, David

Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada b Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada