Alzheimer's disease. Light micrograph of a section through the brain of a patient suffering from Alzheimer's disease. Granulovacuolar degeneration, the presence of vacuoles in the nerve cells (neurones) of the brain, is seen here (small, darkly-stained circles). This is a characteristic feature of the disease, which prevents the neurones from functioning normally. The neurones in the brains of Alzheimer's sufferers degenerate and die, leading to a progressive deterioration in brain function. This is the hippocampus region of the brain, responsible for generating emotion. Magnification unknown.