Immunofluorescent Light Micrograph of a network of neurons and astrocyte cells, in brain cortex. In the foreground, nerve fibres of neurons (green) are seen in a fine branching network. These fibres are the routes of transmission of nerve impulses. Astrocytes behind them (orange) are large star shaped connective tissue cells; as part of the neuroglia (nerve glue) they provide mechanical support and nutrients for the neurons. Astrocytes may take part in information storage processes. Immunofluorescence is a staining technique which uses antibodies to attach fluorescent dyes to specific tissues and to molecules within the cell. Magnification: x200 at 35mm, x375 at 6x4.5cm.