To begin, place the electroencephalogram or EEG electrode implanted anesthetized rat in a supine position. Using a scalpel, make a two to three centimeters long incision from the upper margin of the sternum lengthwise along the middle of the neck. Then, bluntly separate the subcutaneous tissue and sternohyoid muscle, fully exposing the trachea and the longus colli muscles on both sides of the trachea.
Bluntly separate the longus colli muscles from the level of the thyroid gland downward, exposing the first and second cervical vertebrae. Expand the neck area with a rat tissue dilator to fully access the surgical site. Use fine forceps to carefully separate the muscles and tissues visible in the cervical intervertebral space, exposing the location where the vertebra artery enters the first cervical vertebra.
Then, insert the preheated electrocoagulation pen into the area for three to five seconds to electro coagulate and sever the vertebral artery. Separate the muscles and fascia along the inner edge of the sternocleidomastoid muscle. Expose and free the bilateral common carotid artery or CCA and tie a loose knot.
Quickly tighten the first loose knot to block the blood flow in the CCA when the rat regains consciousness and exhibits a righting response. According to the needle control tie method, bind the CCA with a 0.5 millimeter diameter syringe needle, using six-o nylon thread and carefully pull out the needle to render the carotid artery narrowed. After 30 minutes of ischemia, untie the first knot to let the CCA undergo reperfusion.
Untie the second knot to induce CCA stenosis and thereby a sustained coma. Finally, stitch up the incision using a four-o suture. The abrupt blockage of CCA leads to significant suppression of EEG and electromyogram activities, essentially flat-lining, indicating severe impairment.
As bodily compensation improves blood profusion, the rats gradually regain consciousness. Post wake-up, their EEG and electromyogram readings recover almost completely, indicating the reversal of ischemic effects.
