Reproducible Motor Deficit Following Aortic Occlusion in a Rat Model Of Spinal Cord Ischemia
July 22nd, 2017
This study demonstrates the technique to make a minimally invasive and easily reproducible model of spinal cord ischemia in rats. Various degrees of hind limb motor deficit can be produced by controlling the aortic occlusion time.
The overall goal of this procedure is to present the technique to make a spinal cord ischemia model in a rat. Demonstrating the procedure will be done by Mi-Sun Lim. The catheter placed in tail artery is used for monitoring of arterial pressure.
After completing the catheterization, advance the Fogarty catheter through the femoral artery into the descending thoracic aorta. To induce spinal cord ischemia, inflate the Fogarty catheter and drain the blood flow from the carotid artery into the external blood reservoir for controlling proximal arterial pressure. After the scheduled occlusion time, deflate the Fogarty catheter balloon, reinfuse the drained blood and remove the femur catheter.
Once the rat is anesthetized, place the rat in the operating table in the ventral position and maintain anesthesia with spontaneous respiration using a facial mask of inhaled isoflurane Make a horizontal skin incision on the right inguinal area. Using a 4.0 black silk suture, place a loose tie on both proximal and distal ends of the artery to maximize the exposure. While monitoring the arterial pressure through the tail artery, remove the catheters from the femoral and carotid arteries and close the wound with silk sutures.
Hind-limb motor function can be assessed using the motor deficit index. The motor deficit index is defined as the sum of the scores in relation with the lower extremities plus placing/stepping reflex and the maximum deficit is indicated by a score of six. At the assessment of hind-limb motor function at 24 hour after surgery, rats that underwent nine minutes of aortic occlusion showed mild and reversible motor impairment in the hind-limb.
Rats subjected to 10 minutes of aortic occlusion presented moderate motor deficit, but not complete paralysis. Rats that underwent 11 minutes of occlusion time, displayed complete and persistent paralysis. You can induce various degrees of hind-limb motor deficit by controlling the aortic occlusion time using this spinal cord ischemia model.
Once mastered, this technique can be performed within 40 minutes. Thank you for watching and good luck with your experiment.
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Overview
This study demonstrates a technique to create a minimally invasive and reproducible model of spinal cord ischemia in rats. The method allows for the production of varying degrees of hind limb motor deficits by controlling aortic occlusion time.
Key Study Components
Area of Science
- Neuroscience
- Animal Models
- Ischemia Research
Background
- Spinal cord ischemia is a critical condition that can lead to motor deficits.
- Animal models are essential for studying the mechanisms and potential treatments.
- Minimally invasive techniques improve the reproducibility of experiments.
- Controlling occlusion time allows for the study of varying injury severity.
Purpose of Study
- To present a reliable method for inducing spinal cord ischemia in rats.
- To evaluate the impact of different occlusion durations on motor function.
- To facilitate further research in spinal cord injury and recovery.
Methods Used
- Catheterization of the tail artery for arterial pressure monitoring.
- Advancing a Fogarty catheter into the descending thoracic aorta.
- Inflating the Fogarty catheter to induce ischemia.
- Draining blood from the carotid artery to control arterial pressure.
Main Results
- Successful induction of spinal cord ischemia with controlled occlusion times.
- Demonstrated varying degrees of hind limb motor deficits.
- Validated the reproducibility of the model for future studies.
- Provided a framework for assessing recovery post-ischemia.
Conclusions
- The technique offers a minimally invasive approach to study spinal cord ischemia.
- Control over occlusion time is crucial for examining injury severity.
- This model can aid in the development of therapeutic strategies for spinal cord injuries.
