Adrenal medulla, light micrograph. When fixed in chrome salts, stored catecholamine granules oxidize to a brown color, showing the presence of noradrenaline. Other medulla cells secrete adrenaline. Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as a hormone and neurotransmitter.