LENIN'S BRAIN

LENIN'S BRAIN Tilman Spengler (Farrar, Straus & Giroux, $23) This is a disturbingly well-informed novel about brain scientists, genetic theorists, and the Third Reich. A Prussian researcher named Oskar Vogt pursues the secret of intellectual brilliance by cutting into human brains (while ''the head is still warm and the skin easily movable''). He no more finds brilliance than a child breaking a clock finds time, but he's persistent. This dark European best-seller is about prostitution and decadence-not of the body but of the intellect and soul. It's fiction about Nazi Germany. But some of it seems as American as apple pie, sliced as thin as brain tissue on a microscope slide. A -D.A. Ball