Vasculature of rat brain

The image shows a plastic cast of the blood vessels of the rat brain. The vasculature was perfusion fixed and flushed with saline before being filled with a polymer resin. Surrounding tissues were then dissolved to leave a plastic cast of the blood vessels. The larger vessels that appear red are arteries. The red colour comes from a pigment added to the plastic resin. The white material that looks like cotton wool are tiny blood vessels and capillaries. These too are coloured but the are so thin that they appear almost without colour in the photograph. This image was produced as part of a research project investigating how blood pressure is regulated. The researchers are using a rat model of hypertension (high blood pressure) to test the hypothesis that small arteries in the brain stem region of the brain are associated with high blood pressure.