Cerebral Ischemic Coma Model Induced by Modified Four-Vessel Occlusion

The scope of this research is to introduce a model of global ischemic coma, induced by electrical coagulation of the rotoral artery and the temporary coagulation of the common carotid artery simultaneously, which is simple and useful. Friendly for devices. We present and improve the medicine for the modern ischemic coma.

This procedure is easy to perform nervous, friendly, and reduce the risk of secondary trauma effects. Animals shorten the experimental period. Our protocol enable nervous to learn the message of global ischemic coma more quickly, contributing to exploration of a pathologic mechanism and the development of new drugs.

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 longest coly muscles on both sides of the trachea.

Bluntly separate the longest coly 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 vertebral artery enters the first cervical vertebra.

Then insert the preheated electro-coagulation 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 writing response. According to the needle control tie method, bind the CCA with a 0.5 millimeter diameter syringe needle using six oh 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 re-perfusion.

Untie the second knot to induce CCA stenosis and thereby a sustained coma. Finally, stitch up the incision using a four oh 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.