What does a neuron look like up close? Simon (The Heart, 1996, etc.) provides a computer-colored micrograph of neurons taken by an electron microscope magnified 20,000 times. He goes on to explain how billions and billions of neurons link up the body network nervous system connecting brain and nerves throughout the body, making thought, memory, movement, and other functions possible. The author includes information on new scientific equipment and techniques in a difficult text that requires careful, repeated reading, e.g., ""This positron computed tomography (PCT) photo uses radioactive tracers in blood sugar to show two different levels of visual stimulation in the brain."" Full-color photographs, computer simulations, drawings, and three-dimensional models are used to grand effect to clarify, explain, and celebrate the remarkably complex system of brain and nerves; the large format, often with white type on black paper and full-page photos, is visually striking. Those who persevere (with no glossary or index to guide them) will appreciate this fascinating title, a case in which the picture-book format works perfectly to complement text with illustrations, but by no means indicates simplicity.