Charles Scott Sherrington helped to found the discipline of neurophysiology by his research on how nerve impulses are transmitted between the central nervous system and muscles. Sherrington focused much of his career on understanding the structure and the function of the nervous system. Drawing on the research of Spanish neuroanatomist Santiago Ramón Cajal, Sherrington proposed viewing nervous activity as part of an integrated and complex system. For his work on how the central nervous system elicits motor activity from muscles, Sherrington shared the 1932 Nobel Prize in physio__logy or medicine with Edgar Douglas Adrian.
Born November 27, 1857, in London, England, Sherrington was the son of James Norton and Anne (Brookes) Sherrington. James Sherrington died while his son was still very young, and later Sherrington's mother married Caleb Rose, Jr., a physician in Ipswich, England. Rose was broadly and classically educated, and his home served as a gathering place for artists, writers, and scholars. Exposure to these diverse arts influenced Sherrington and was reflected in his own broad interests in the humanities and the sciences. After attending Ipswich Grammar School, Sherrington began medical training in 1875 at St. Thomas's Hospital in London. In 1879 he enrolled in Caius College at Cambridge University. Two years later, Sherrington began work in the laboratory of Michael Foster, England's foremost physiologist. In Foster's laboratory, Sherrington also met John Newport Langley, Newell Martin, Walter Gaskell, and Sheridan Lea, individuals who would become important physiologists in their own right.
Proposes an Integrated Nervous System
After earning a bachelor's degree in medicine in 1884, Sherrington left Cambridge to pursue graduate studies in German laboratories. He remained abroad for three years, receiving training and conducting research in physiology, histology, and pathology, and working in the laboratories of Rudolf Virchow, Robert Koch, and Friedrich Goltz, with whom he studied the central nervous system. Upon returning to England, Sherrington assumed a post teaching systematic physiology to medical students at his training site, St. Thomas's Hospital in London. He left this position in 1891 to become professor and superintendent of the Brown Institute for Advanced Physiological and Pathological Research. A year later, Sherrington married Ethel Mary Wright; their only child, Charles E. R. Sherrington, was born in 1897.
Sherrington accepted the physiology chair at the University of Liverpool in 1895. Seeking to understand the structures and the mechanisms that operated the nervous system, Sherrington began to draw on the work of Ramón y Cajal. Prior to the latter scientist's work in the late 1880s, neurophysiologists believed that nerve fibers formed a continuous network or system through the body. This proposition was known as the reticular theory. Ramón y Cajal refuted the reticular theory by using a silver-based dye developed by the Italian anatomist Camillo Golgi. Golgi's preparation stained individual nerve cells a black color and demonstrated to neuroanatomists that nerve cells were discrete entities and not part of a nexus as was previously thought. The new theory that saw nerve cells as independent units was called the neuron theory, or popularly, the neuron doctrine. Although nerve cells were discrete units, neurons in a series could form pathways through which information can be transmitted. Nerves--consisting of a bundle of fibers--relay sensations (like touch and smell) and instructions on motor activity (like moving an arm or a leg) by electrical impulses. Sherrington became interested in understanding how nerves formed integrative pathways between the central nervous system and muscles. He considered some simple reflexive behavior, such as the knee-jerk, and attempted to explain the neurophysiology of the phenomena. Finding that he had an insufficient knowledge of neural anatomy to conduct the research, Sherrington stoically devoted the next decade to mapping the pathways between the central nervous system and muscle groups and to identifying the sensory nerves that innervated muscle tissue.
Sherrington's commitment to understanding the neural pathways proved to have an important impact. He came to realize that a particular reflexive behavior was not controlled by a single pathway or an isolated response to a single stimulus. Rather, a simple reflex was the product of a complex process that involved the inhibition and excitation of many nerve cells in many different pathways. Sherrington concluded that the central nervous system was an integrated whole that coordinated multiple pathways to produce any single action. His contributions on this point were not only theoretical but experimental. He introduced seminal research strategies for studying questions of the central nervous system. For example, the spinal animal, an animal with a transected spinal cord, and the decerebrate rigid animal, an animal partially paralyzed by the excision of the cerebral cortex, were introduced as important approaches to exploring the activity of the nervous system. Sherrington's analysis of the hind limb scratch of a dog helped to elucidate neuronal action.
Continues Explorations of the Central Nervous System
Sherrington's study of the scratch reflex in dogs elucidated other important principles of how the central nervous system is organized. He concluded that reflexes can have "reciprocal innervation" so that inhibitory and excitatory reflexes are coordinated simultaneously. Sherrington also concluded that there are two levels on which actions are controlled--higher level control by the brain and lower level control by the muscle nerves. His most important idea perhaps reflected in the integrative scheme is that there is a break between one nerve cell and another, between brain and muscles, between inhibitory and excitatory processes. To describe this break, Sherrington coined the term "synapse." The idea of a synapse became important for two reasons. First, it acknowledged that nerve cells were not organized in the reticular fashion as it was previously argued. Second, understanding how synapses were transcended became the next challenge for twentieth-century neurophysiologists. Sherrington lucidly offered these ideas about the nervous system in his seminal work, The Integrative Action of the Nervous System, published in 1906.
In 1913 Sherrington left the University of Liverpool after eighteen years of service to assume the Waynflete Professorship of Physiology at Oxford University. The post offered Sherrington the opportunity to continue his research on the central nervous system, but the entry of Great Britain into World War I in August, 1914, meant Sherrington had to postpone his studies for some time. He joined the war effort, serving as chair of the Industrial Fatigue Board. Not satisfied with merely reading about the conditions of war-time industrial workers, in 1915 Sherrington worked incognito in a shell factory to experience first-hand the hardships and long shifts faced by workers. Although he managed to complete a textbook of physiology during the war period, Sherrington did not return to his normal research work until the mid-1920s. He successfully recruited a number of promising assistants, including E. G. T. Liddell and John Carew Eccles. Eccles would go on to win the 1963 Nobel Prize in physiology or medicine for research that had its roots in his stint in Sherrington's Oxford laboratory. Eccles, Liddell, and Sherrington's other students grew in reputation as the "Sherrington school," and their assistance allowed Sherrington to complete a minimum of an experiment a week.
Sherrington's research at Oxford after the 1920s differed from the work that he had been doing prior to World War I. Rather than studying the nervous system as a whole, Sherrington focused his attention on specific mechanisms in the central nervous system. He developed with Eccles the idea of a "motor unit" --a nerve cell that coordinates many muscle fibers. He also concluded that neuronal excitation and inhibition were separate and distinct processes; one was not merely the absence of the other.
Leads an Active Life During Retirement
Although Sherrington retired in 1936, four years after being named a Nobel Prize-winner, he maintained an active life after his formal retirement. He cultivated many of the interests that he had as child in the eclectic home of his stepfather, including poetry, history, and philosophy. In 1925 Sherrington wrote and published a book of poems titled The Assaying of Brabantius. His deep interests in philosophy and history were reflected in two post-retirement publications, 1941's Man on His Nature and 1946's The Endeavor of Jean Fernel. In addition to being a popular and sought-after speaker, Sherrington was a trustee of the British Museum in London and served as governor of the Ipswich School from which he had graduated.
In addition to the Nobel Prize, Sherrington garnered virtually every honor that could be given to a British scientist. At the time of his death in 1952, he held memberships in more than forty scholarly societies and had been given honorary degrees from twenty-two universities. Most notably, Sherrington was a past president of the Royal Society of London (1920-1925), and recipient of the Knight Grand Cross of the British Empire in 1922 and the Order of Merit in 1924. He died on March 4, 1952, from heart failure.
This is the complete article, containing 1,445 words
(approx. 5 pages at 300 words per page).
