Measuring the Infarct Zone and Brain Edema in a Rat Brain Following Middle Cerebral Artery Occlusion

Take a rat subjected to middle cerebral artery occlusion, restricting blood flow to the right brain hemisphere.

Reduced blood supply deprives brain cells of oxygen, disrupts water regulation, causes cell swelling or edema, and leads to blood-brain barrier disruption.

Damaged cells eventually die, forming an infarct zone.

Inject a blue dye into the rat's tail vein to detect BBB disruption.

Harvest the brain, slice it with razor blades, and incubate the slices in a redox dye solution.

In living cells, the dye reacts with mitochondrial dehydrogenases and undergoes reduction, turning viable tissue red.

Infarcted areas, lacking dehydrogenase activity, remain white.

Scan the slices to obtain high-resolution images.

Using image analysis software, apply a blue filter to eliminate the blue dye color, converting the images to grayscale.

Apply thresholding to distinguish healthy black tissue from infarcted white tissue.

Calculate the infarct zone and brain edema as a percentage of the unaffected contralateral hemisphere.

To begin, remove the rat brain and cut 2 millimeter thick horizontal sections with a 0.009-inch stainless steel uncoated single-edge razor blade. Place the sections in 0.005%