Calibrated Forceps Model of Spinal Cord Compression Injury

The overall goal of the following experiment is to demonstrate the steps necessary to generate a reproducible spinal cord compression injury in mice using calibrated forceps. This is achieved by delicately removing the skin and muscle layers over the spinal column and identifying the correct vertebral target. Next, a laminectomy is performed on the targeted vertebrae to expose the spinal cord and then calibrated forceps are used to produce the spinal cord injury.

The results illustrate the extent of the damage within spinal cord tissue following a spinal cord compression using histochemical techniques. Generally, individuals who are new to this method are going to struggle. You're performing a very delicate procedure on a small animal with little margin for error.

This is a sensitive tissue, and you may accidentally inflict a more serious injury than intended, so you may want to practice first To prepare for surgery, assemble of the following, surgical tools and reagents, forceps, van scissors, URS scalpels, retractor sutures, skin staples, Q-tips, sterile saline, surgical sponges, and isof fluorine, which is used in conjunction with an anesthesia machine. Autoclave the tools for a single surgery and use a tool sterilizer to sterilize the tools between surgeries. Use 70%isopropyl alcohol to disinfect the surgical field and set up surgical drapes to ensure sterile field is maintained during surgery.

After weighing each mouse prior to surgery, administer a dose of 0.05 milligrams per kilogram body weight of buprenorphine subcutaneously once the animal has been anesthetized, according to the text protocol, apply ointment to the eyes to prevent dehydration and shave the dorsal surface of the mouse approximately one centimeter around the intended incision location. To disinfect the incision site, use an iodine solution followed by 70%isopropyl alcohol. Repeat three times to begin surgery.

First, perform a toe or a tail pinch to assess reflexes. If none are present. Use a scalpel to make an incision along the dorsal spine, cutting through the skin.

Insert the retractor to hold the skin back from the spinal cord. Check for reflexes again. Then clear the tissue on either side of the spinal cord to expose the muscles covering the spine arch the back to help properly visualize landmarks such as the boundaries between vertebrae.

The following landmarks should be visible. The inferior angle of the scapula, which corresponds to T seven and the top of the natural curve of the mouse's spinal cord at TT 12 with proper lighting. Determine the space between the vertebrae.

Then find the posterior end of T 10 and cut just enough muscles and fascia perpendicular to the intervertebral disc space to expose the spinous process and posterior lamina of T 10 using a pair of fine tips, Dumont number five, forceps. Remove some of the tissue from the lamina and spinous process to expose a small sliver of the spinal cord. When necessary, use tissue forceps to stabilize a spinal column.

Next, perform the laminectomy by inserting one side of a pair of small VNA scissors along the dorsal lateral side of the vertebra just beneath the lamina. Then make small careful snips to cut through the leftal side of the vertebral lamina. Repeat on the other side.

Ensure that no pressure is applied to the spinal cord with a cotton swab or surgical sponge. Apply gentle pressure to halt bleeding as necessary. Taking care not to apply pressure to the spinal cord.

Once the incisions have been made, lift off the dorsal aspect of the vertebra and gently clear any tissue attachments. Use appropriate means to control bleeding if necessary. Using wrong jaws or laminectomy forceps, ensure that the lateral sides of the spinal cord are free of vertebral bone so that the calibrated forceps for the compression injury can situate properly on either side of the spinal cord.

Now situate the calibrated dumont. Number five, forceps approximately in the middle of the exposed segment of the spinal cord with the arms of the forceps within the epidural space and the tips touching the floor of the vertebral canal. Carefully compress the spinal cord until the spacers connect and hold in place for 15 seconds.

Then gently release a compressive force and remove the calibrated forceps from the spinal cord. Apply sterile saline to regain homeostasis and carefully suture the muscle layer over the spinal cord. Taking care not to disrupt or apply pressure to the spinal cord.

Use either sutures or staples to close the skin over the wound administer. Point one milliliter of lactated ringers per 10 grams of body weight to help with dehydration. Before placing the mouse in a bedding free cage on a heating pad set to approximately 37 degrees Celsius.

In a quiet environment, closely monitor the animal until it is regained consciousness. Then transfer it to a regular cage with bedding for the first three days after surgery, administer a dose of 0.05 milligrams per kilogram body weight of buprenorphine subcutaneously every 12 hours, and then as needed to manage symptoms of pain twice daily. Use decreed maneuver to manually express the bladder of the animal by gently palpating the animal's abdomen to locate the bladder and apply gentle downward pressure until the bladder is empty.

Because of the animal's reduced mobility right after surgery, take the necessary steps to give the animal access to food and water by providing wet food and hydrogel. Refer to the text protocol for assessing tissue damage laminectomy and spinal cord compressions at point 25 millimeters. Point 35 millimeters or point 55 millimeters were carried out on 12 mice, and they were sacrificed at three or seven days post-injury by intracardiac perfusion as seen here.

Spinal cord compression produces injuries with the epicenter at the site of compression and the effects of the injury extend several millimeters in the rostral and coddle direction. This figure shows that the severity of the injuries increased as the distance between the spacers decreased. For example, the point 25 millimeter and point 35 millimeter compressions produced a cavity not seen in the point 55 millimeter model three days after compression, there was blood at the epicenter of the injury and surrounding regions that was not present seven days after injury after seven days, the dorsal and ventral white matter largely decreased in size at the epicenter.

The gray matter organization was highly distorted and cavitation was persistent as previously demonstrated, the cyto architectonic translate into motor and sensory alterations in animal behavior, evaluated by the besso mouse scale for locomotor function, and the von Frey hair and ethyl chloride tests for sensory function. After this procedure, you can perform additional methods such as the direct transplantation of cells or the injection of other therapeutic reagents into the spinal cord to answer additional questions such as whether that particular therapy can improve the outcome after spinal cord injury.