Sir Charles Scott Sherrington Research Paper

To characterize the broad span of Sherrington’s engagement he should be described as ‘Pathologist, Physiologist, Philosopher and Poet.’ It is somewhat arbitrary to pick out only two of them because it is the combination of all these elements that made him both great and unique. However, hardly any other physiologist since 1800 made such a fundamentally important contribution to the knowledge and to the development of concepts in modern neurophysiology. Moreover, when advanced in years, he was the first to attempt a contribution to the solution of the age-old problem of brain/body and mind on a well-founded neuroscientific basis.

1. The Life

Born in London on November 27, 1857, Sherrington was brought up in Ipswich and Norwich. From his earliest years he felt a strong attraction to poetry, a love which never left him throughout his life. Some of his poems were published in various magazines and later were partly collected in a small volume (Sherrington 1925).

In 1876 Sherrington first enrolled at St. Thomas’ Hospital Medical School in London and in 1881 matriculated at Cambridge University, where he received his B.A. in 1884 and his M.D. in 1885. During his undergraduate years he started his research in neuroanatomy and neuropathology, publishing his first papers on these studies in 1884 together with John Newport Langley (Langley and Sherrington 1884). This was the beginning of a very productive publishing activity with almost 320 scientific publications (for Sherrington’s complete Bibliography: see Fulton 1952). During his initial postgraduate period at Cambridge Sherrington‘s scientific interests concentrated on neurohistology and pathology. This period was interrupted by expeditions to epidemics of Asian Cholera in Spain and Italy. The autopsied material taken during these expeditions he analyzed together with J. Graham Brown and Charles vs. Roy in England (1885) and with Rudolf Virchow and Robert Koch in Germany (1886). In 1890 Sherrington was appointed lecturer in physiology at St. Thomas’ Hospital in London where he mainly performed clinical work. A year later he received the position of the Professor-Superintendent at the Brown Institute at the University of London, where he became remarkably productive with a variety of publications which reflected his pathological, but also his increasing neurophysiological interest. In 1895 Sherrington received his first appointment to a full professorship of physiology at the University College in Liverpool, where he investigated intensely the organization of the spinal cord.

At age 56 (in 1913) Sherrington entered probably the busiest period of his scientific career when he was appointed to the chair of physiology at Oxford University, from which he did not retire until 1935, when he was 78. It was during his Oxford time that he, together with Edgar Adrian, received the Nobel Prize for Medicine in 1932 (the greatest tribute among numerous honours and rewards, like, for example the Presidency of the Royal Society 1920–25, some 21 international honorary doctorates, and many medals and honorary memberships of British and international societies and academies, among these the corresponding membership of l’Institut de France). Three of his students at Oxford were later Nobel Prize winners: Howard Walter Florey, John Carew Eccles and Ragnar Granit.

In the early 1930s Sherrington performed his last physiological experiments and he felt free to turn to his other great love, the philosophy of the nervous system. Having retired to his old hometown of Ipswich in 1935, his scientific interest was increasingly enriched by philosophical considerations that became evident in the Gifford Lectures, held between 1937 and 1938. Obviously, it was also Sherrington’s interest in Natural Philosophy that caused him to work on Goethe (Sherrington 1942) and Jean Fernel, a French physician and philosopher of the sixteenth century (Sherrington 1946).

Though his body was crippled by arthritis, his intellectual capacities remained undimmed until his death in Eastbourne on March 4 1952.

2. The Physiologist

Regarding the nervous system as a functional unity resulting from its well-organised parts, Sherrington investigated a variety of motor and sensory systems: the topographical organisation of the motor cortex, the binocular integration in vision, as well as the different receptor systems. However, his main efforts concentrated on the spinal cord and its reflex function in motor control. He explicitly admitted that spinal reflex behaviour is not ‘the most important and far-reaching of all types of nerve behavior’ but represents the advantage that ‘it can be studied free from complication with the psyche’ (Sherrington 1906 1947, Foreword, p. xiii).

In the spinal cord, isolated from the brain, he carefully analyzed almost all spinal reflex-types from the ‘simple’ two-neurone reflex arc of the stretch reflex (first described by him), via the complex partly nociceptive flexion and crossed extension reflex and co-ordinated rhythmic scratching and stepping reflexes, up to goal-directed reflex movements of the limbs towards irritating stimuli. Right from the beginning he demonstrated that spinal reflexes are not following a stereotyped all-or-nothing behavior, but that the adaptability of reflexes, based on graduated amplitude, irradiation, and mutual interference between different reflex types, is of great importance for motor control. Sherrington was the first to suggest that inhibition had at least the same functional importance for motor coordination—and other nervous functions—as excitation, not only at the spinal level but also at the brain level and for descending motor commands. This view also opened up new insights into the background of motor disorders observed in various neurological syndromes.

Though some of the reflexes and other motor and sensory phenomena described by Sherrington had been noted earlier, his experimental observations and their analyses were altogether more exact and careful than those of former investigations. Thus, he disproved e.g., several of Pflugers’s reflex laws and the assumption of Descartes (1677) and John and Charles Bell (1826) that reciprocal inhibition is localized peripherally in the muscle. However, the higher experimental sophistication alone would not for sure have received that particularly high enduring recognition. Indeed, Sherrington’s most important contribution to neuroscience resulted from his unique capability to condense his immense knowledge on sensory and motor functions and on the structure of the nervous system (partly derived from an intense contact with the famous Spanish neurohistologist Santiago Ramon y Cajal) in an almost visionary synopsis of the integrative action of the nervous system, which laid the foundation for the great progress of neuroscience in the twentieth century and which has lost none of its basic validity. This synopsis made his book The Integrative Action of the Nervous System (1906) a milestone in neurophysiology, which has been compared ‘in importance with Harvey’s’ 300 years older ‘De motu cordis in marking a turning point in the history of physiological thought’ (Fulton 1952, p. 174). For Sherrington, spinal reflexes did not have a ‘purpose’ but a ‘meaning.’ He replaced the formerly presumed ‘soul’ of the spinal cord (e.g., Legallois 1812, Pfluger 1853) as the driving force for reflexes and even voluntary movements by an astonishing exactly considered function of spinal interneuronal activity. He replaced the Cartesian reflex behaviorist view by the still-relevant view that the performance of coordinated movements as a basis for animal and ‘conscious’ human behavior requires an integration of ‘intrinsically’ generated brain functions with ‘extrinsically’ induced reflex functions. In this context he suggested that the pure ‘apsychical’ reflex behavior without a contribution of ‘mind’ loses in importance with phylogenetic ascendance, playing the smallest role in man: ‘The spinal man is more crippled than is the spinal frog’ (Sherrington 1906/1947, Foreword, p. xiv).

As a true scientist Sherrington never felt that he had arrived at any incontrovertible truth and in a typically unpretentious understatement he concluded: ‘I have dealt very imperfectly with a small bit of a large problem…. The smallness of the fragment is disappointing’ (1931 p. 27); this a statement from a man about whom Frederick George Donnan wrote in 1921 to the Nobel Committee: ‘In the field of physiology and medicine, Professor Sherrington’s works remind one of that of Kepler, Copernicus and Newton in the field of mechanics and gravitation’ (in H. Schuck et al., 1962, p. 310).

3. The Philosopher

Like for example, Descartes before and Eccles after him, Sherrington realised that mere experimental investigation of the nervous system was not sufficient to solve the fundamental problem of the body/brain–mind relation, particularly the difficulty of explaining how it actually works. In the Rede Lecture on The Brain and its Mechanism (Sherrington 1933) in which he considered the complexity of the brain functions in motor control and behavior and in which he tentatively approached this problem, Sherrington took a fully dualistic view. He even negated any scientific right to ‘conjoin mental experience with the physiological…. The two … seem to remain disparate and disconnected’ (1933, pp. 22–3).

But later in the Gifford Lectures, which he held in Edinburgh in 1937–1938 (published as Man on his Nature in Sherrington 1940 and as an extensively revised new edition in 1951) he took up the great enigma of the brain–mind relation in the light of his new neuroscientific knowledge. Rejecting the assumption of a mysterious mind of a ‘heavenly’ origin he stated, ‘Ours is an earthly mind which fits our earthly body’ (Sherrington 1940, p. 164). ‘Mind’ for Sherrington was coupled to motor acts, ‘mind’ only being recognizable via motor acts. He suggested that ‘mind’ is graduable, that a recognizable ‘mind’ is developing in the developing brain in humans and to varying degrees in animals. Regarding the relation between the two concepts of ‘energy’ (assuming ‘matter’ also as ‘energy’ in the physical sense) and ‘mind’, he concluded that ‘mind’ as a function of the living brain is mortal, while the ‘energy’ the matter—is immortal, just changing its state when the brain is dying. In his discussions he entirely avoided the complicating problem of an ‘immortal soul’, which he, as being himself oriented towards Natural Religion, left to the Revealed Religions: ‘When on the other hand the mind-concept is so applied as to insert into the human individual an immortal soul, again a trespass is committed’ (Sherrington 1940, p. 355).

When Sherrington with something like resignation stated, ‘But the problem of how that [body-mind] liaison is effected remains unsolved; it remains where Aristotle left it more than 2000 years ago’ (Sherrington 1906/1947, Foreword, p. xxiii) he probably underestimated the contribution of his step towards the direction of a solution by defining ‘mind’ as a function of the brain requiring a complex integrative action of the nervous system; a view which was taken up and further developed by one of his students, Sir John C. Eccles (1970, Eccles and Gibson 1979).

4. And Now?

As stated in Sect. 3 the experimentally well-based theories and concepts, which Sherrington had creatively developed with great visionary imagination, formed a well-recognised secure foundation for future developments in the neurosciences.

The half-century after Sherrington’s death has brought an immense increase in neuroscientific knowledge. First, particularly, the technique of microrecordings from nerve cells and the analysis of ionic membrane mechanisms confirmed and extended the knowledge and hypotheses based on Sherrington’s activities on brain and spinal functions in sensory perception, motor control, and behavior. Then new techniques allowed for analytic investigation of more and more detailed neuronal structures, functions, and interactions down to the molecular level. New gentechnical approaches enabled the ‘production’ of innumerable variants of mice with defined genetic defects at the molecular level.

However, the bewildering mass of results originating from these experiments opened up a host of new questions. What is required now is a new ‘Sherringtonian’ approach which comprises a complex critical analysis of today’s entire neuroscientific knowledge (from molecular mechanisms up to the level to complex behaviour) in an integrative synopsis and which develops new concepts to explain the sophisticated brain functions and their relation to mind as expressed by behavior. Despite the exponential increase in detailed neuroscientific knowledge, we have not really come closer to a solution of that problem since Sherrington.

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