<P> Andreas Vesalius noted many structural characteristics of both the brain and general nervous system during his dissections of human cadavers . In addition to recording many anatomical features such as the putamen and corpus collusum, Vesalius proposed that the brain was made up of seven pairs of' brain nerves', each with a specialized function . Other scholars furthered Vesalius' work by adding their own detailed sketches of the human brain . René Descartes also studied the physiology of the brain, proposing the theory of dualism to tackle the issue of the brain's relation to the mind . He suggested that the pineal gland was where the mind interacted with the body after recording the brain mechanisms responsible for circulating cerebrospinal fluid . Thomas Willis studied the brain, nerves, and behavior to develop neurologic treatments . He described in great detail the structure of the brainstem, the cerebellum, the ventricles, and the cerebral hemispheres . </P> <P> The role of electricity in nerves was first observed in dissected frogs by Luigi Galvani in the second half of the 18th century . In the 1820s, Jean Pierre Flourens pioneered the experimental method of carrying out localized lesions of the brain in animals describing their effects on motricity, sensibility and behavior . Richard Caton presented his findings in 1875 about electrical phenomena of the cerebral hemispheres of rabbits and monkeys . Studies of the brain became more sophisticated after the invention of the microscope and the development of a staining procedure by Camillo Golgi during the late 1890s that used a silver chromate salt to reveal the intricate structures of single neurons . His technique was used by Santiago Ramón y Cajal and led to the formation of the neuron doctrine, the hypothesis that the functional unit of the brain is the neuron . Golgi and Ramón y Cajal shared the Nobel Prize in Physiology or Medicine in 1906 for their extensive observations, descriptions and categorizations of neurons throughout the brain . The hypotheses of the neuron doctrine were supported by experiments following Galvani's pioneering work in the electrical excitability of muscles and neurons . In the late 19th century, Emil du Bois - Reymond, Johannes Peter Müller, and Hermann von Helmholtz showed neurons were electrically excitable and that their activity predictably affected the electrical state of adjacent neurons . </P> <P> In parallel with this research, work with brain - damaged patients by Paul Broca suggested that certain regions of the brain were responsible for certain functions . </P> <P> Neuroscience during the twentieth century began to be recognized as a distinct unified academic discipline, rather than studies of the nervous system being a factor of science belonging to a variety of disciplines . </P>

When did the study of the brain begin