Introduction

Research on the structure and function of the human brain started very early in the history of medical science. Greek doctors, in the sixth century BC, recognized the brain as the center of the highest human activities. At the time of Galen in the second century AD, brain anatomy was already known in detail, and the brain’s importance was established as the seat of intelligence, voluntary movements, and sensations. The composition of the brain generated a significant interest as early as the time of Plato (428–348 BC), who considered this body part as equal to the bone marrow, whereas Aristotle (384–322 BC) compared the brain to a fat deposit comparable to the spermaceti found in the brain of the sperm whale.