vestibular apparatus, attended this school, graduating in 1900. Obersteiner was later superseded by Otto Marburg. Twentieth century 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. Ivan Pavlov contributed to many areas of neurophysiology. Most of his work involved research in temperament, conditioning and involuntary reflex actions. In 1891, Pavlov was invited to the Institute of Experimental Medicine in St. Petersburg to organize and direct the Department of Physiology. He published The Work of the Digestive Glands in 1897, after 12 years of research. His experiments earned him the 1904 Nobel Prize in Physiology and Medicine. During the same period, Vladimir Bekhterev discovered 15 new reflexes and is known for his competition with Pavlov regarding the study of conditioned reflexes. He founded the Psychoneurological Institute at the St. Petersburg State Medical Academy in 1907 where he worked with Alexandre Dogiel. In the institute, he attempted to establish a multidisciplinary approach to brain exploration. The Institute of Higher Nervous Activity in Moscow, Russia was established on July 14, 1950. Charles Scott Sherrington's work focused strongly on reflexes and his experiments led up to the discovery of motor units. His concepts centered around unitary behaviour of cells activated or inhibited at what he called synapses. Sherrington received the Nobel prize for showing that reflexes require integrated activation and demonstrated reciprocal innervation of muscles (Sherrington's law). Sherrington also worked with Thomas Graham Brown who developed one of the first ideas about central pattern generators in 1911. Brown recognized that the basic pattern of stepping can be produced by the spinal cord without the need of descending commands from the cortex. Acetylcholine was the first neurotransmitter to be identified. It was first identified in 1915 by Henry Hallett Dale for its actions on heart tissue. It was confirmed as a neurotransmitter in 1921 by Otto Loewi in Graz. Loewi demonstrated the ″humorale Übertragbarkeit der Herznervenwirkung″ first in amphibians. He initially gave it the name Vagusstoff because it was released from the vagus nerve and in 1936 he wrote: ″I no longer hesitate to identify the Sympathicusstoff with adrenaline.″ One major question for neuroscientists in the early twentieth century was the physiology of nerve impulses. In 1902 and again in 1912, Julius Bernstein advanced the hypothesis that the action potential resulted