Light micrograph of normal human spinal cord, showing part of the grey matter of the anterior horn. Two neurons (nerve cells) are visible, each with a dark-stained nucleous and associated with a mass of nerve fibres. The scattered rose-purple particles in the background are the nuclei of neurological cells; their cytoplasm is unstained. They lie within a field of intercrossing nerve fibres, seen as delicate pale blue lines. This region of neurological cells and nerve fibres is known as the neuropil. Magnification x100 at 35mm size.