Widely acknowledged to be the first person to make detailed studies of microscopic objects, the pioneering work of Antonie van Leeuwenhoek (1632-1723) provided the first glimpse of neurons when he observed sections of bovine optic nerves (van Zuylen, 1981). It was over a century later when the Italian scientist Camillo Golgi (1843-1926) developed la reazione nera (‘the black reaction’), later dubbed the Golgi stain or Golgi method, in 1873. This approach revealed a hitherto unseen world, one brought to light in stunning fashion in the decades that followed by Santiago Ramon y Cajal (1852-1934), who refined Golgi’s techniques and published numerous articles detailing the fine structure of the nervous system (Ramon y Cajal, 1995). The inescapable conclusion of this work that the nervous system is composed of discrete cellular units, or neurons, that communicate with one another in a vast network came to be known as ‘the neuron doctrine.’ It is from these initial findings that the sophisticated techniques available to today’s scientists are descended.