This confocal micrograph shows the detailed structure of the retina from a one-month-old mouse. The retina is the photoreceptive organ of the eye. It is composed of layers of neuronal cells that capture and transmit the light information, converting it into electrical signals that the brain can interpret. Fluorescent markers have been used to highlight different classes of these cells within the retina. Green staining highlights glial cells, which act as neuronal supporting cells and produce myelin, the protective conductive layer that surrounds the axons of the neurons. The red fluorescently labelled protein marks astrocytes, star-shaped glial cells that provide nutrients to developing neurons and regulate neuronal activity. The blue fluorescence marks cell nuclei. This image was created as part of a study to examine the stress observed in the retina as a result of oxygen deprivation. These studies are helping scientists to understand why premature babies develop retinal disease when born too early. 2011 Wellcome Images Award winner.