Skeletal changes affecting the nervous system produced in young dogs by diets deficient in vitamin A / by Edward Mellanby.

  • Mellanby, Edward, Sir, 1884-1955.
Date:
[1941?]
Catalogue details

Licence: In copyright

Credit: Skeletal changes affecting the nervous system produced in young dogs by diets deficient in vitamin A / by Edward Mellanby. Source: Wellcome Collection.

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    J. Physiol. (1941), 467-486 612.392.013:612.753:612.8 SKELETAL CHANGES AFFECTING THE NERVOUS SYSTEM PRODUCED IN YOUNG DOGS BY DIETS DEFICIENT IN VITAMIN A By EDWARD MELLANBY Nutrition Building, National Institute for Medical Research, Mill Hill, London (Received 19 December 1940) I. Introduction The production under controlled conditions of tissues abnormal in structure or function, or in both, and the prevention of the abnormalities by defined alterations in these conditions have sometimes led to the accession of knowledge both to the physiologist and pathologist. The present paper deals with an instance of this type of experiment. In previous publications detailed descriptions have been given of the widespread degeneration of the central and peripheral nervous systems, especially of young animals brought up on diets deficient in vitamin A and carotene and rich in cereals [Mellanby, 1926, 1931, 1933, 1934, 1935]. Although these degenerative changes were thought at first to be directly due to the destructive effect of vitamin A deficiency on the nervous system, evidence was subsequently forthcoming to suggest that they were indirectly produced and were really due to bone overgrowth in the vicinity of the affected nerves and nerve cells and to the pressure effects resulting therefrom. In particular, a study of the eighth nerve and the labyrinthine capsule [Mellanby, 1938] demonstrated that a dietary deficiency of vitamin A resulted in bony overgrowth of the periosteal layer of the labyrinthine capsule, especially of that part surrounding the internal modiolus, and the evidence strongly suggested that the pressure due to this overgrowth was responsible for the nerve degeneration. At a later date, evidence was also given of bony overgrowth surrounding the optic and trigeminal nerves and of other bones in close proximity to the brain and spinal cord [Mellanby, 1939u, 6]. Although it cannot yet be claimed that this sequence of events fully explains all the widespread 31—2