Brain cells. Fluorescence light micrograph of a section through tissue from the hippocampus of the brain, showing numerous glial cells (red and green) and neurons (nerve cells, blue cell nuclei). The hippocampus is a region of the brain critical for memory formation. It is a complex structure with highly organised neuronal layering, interspersed with supporting glial cells. Glial cells, or neuroglia, are non-neural cells of the central nervous system (CNS, brain and spinal cord). They are the predominant cell type in brain tissue. They provide physical and functional support to neurons. This image shows two types of glial cells, astrocytes (green) and microglia (red).