History of neuroscience
During the second half of the first millennium BC, the Ancient Greeks developed differing views on the function of the brain. However, due to the fact that Hippocratic doctors did not practice dissection, because the human body was considered sacred, Greek views of brain function were generally uninformed by anatomical study. It is said that it was the Pythagorean Alcmaeon of Croton (6th and 5th centuries BC) who first considered the brain to be the place where the mind was located. According to ancient authorities, "he believed the seat of sensations is in the brain. This contains the governing faculty. All the senses are connected in some way with the brain; consequently they are incapable of action if the brain is disturbed...the power of the brain to synthesize sensations makes it also the seat of thought: The storing up of perceptions gives memory and belief and when these are stabilized you get knowledge." In the 4th century BC Hippocrates, believed the brain to be the seat of intelligence (based, among others before him, on Alcmaeon's work). During the 4th century BC Aristotle thought that, while the heart was the seat of intelligence, the brain was a cooling mechanism for the blood. He reasoned that humans are more rational than the beasts because, among other reasons, they have a larger brain to cool their hot-bloodedness.
Human brain
In the late 19th century, Emil du Bois-Reymond and Hermann von Helmholtz, following the work of their teacher Johannes Peter Müller showed the electrical inpulses which pass along nerves; but unlike Müller's views, that such impulses were able to be observed. Richard Caton in 1875 demonstrated electrical impulses in the cerebral hemispheres of rabbits and monkeys. In the 1820s, Jean Pierre Flourens pioneered the experimental method of damaging specific parts of animal brains describing the effects on movement and behavior.
Studies of the brain became more sophisticated with the use of the microscope and the development of a silver staining method by Camillo Golgi during the 1880s. This was able to show the intricate structures of single neurons. This was used by Santiago Ramón y Cajal and led to the formation of the neuron doctrine, the then revolutionary hypothesis that the neuron is the functional unit of the brain. He used microscopy to uncover many cell types, and proposed functions for the cells he saw. For this, Golgi and Cajal are considered the founders of twentieth century neuroscience, both sharing the Nobel prize in 1906 for their studies and discoveries in this field.