Are these the veins of a leaf? Or maybe a strange map? In fact this is the delicate network of blood vessels in the light-sensitive layer at the back of a mouse's eyeball, known as the retina, artificially coloured and viewed down a microscope. The retina is packed with light-sensing cells as well as nerve cells that send signals to the brain telling it what the animal is seeing, and they need plenty of oxygen and nutrients from the blood. Researchers are studying how these fragile tubes grow in order to understand more about what can go wrong if there are problems with the heart or circulation. For example, high blood pressure can cause damage or tiny blood clots can get stuck in them, leading to sight loss.
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.