Lesions of the central and peripheral nervous systems produced in young rabbits by vitamin A deficiency and a high cereal intake / by Edward Mellanby.

  • Edward Mellanby
Date:
[1935?]
Catalogue details

Licence: In copyright

Credit: Lesions of the central and peripheral nervous systems produced in young rabbits by vitamin A deficiency and a high cereal intake / by Edward Mellanby. Source: Wellcome Collection.

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    perhaps the most consistent changes. In the well-established cases of carotene deficiency it is rare to see many Purkinje cells in which some change is not apparent. The nucleus becomes cloudy and can often only be recognized by means of the nucleolus, the demilune merges into the rest of the protoplasm and cannot be differentiated, the cell edges become frayed and sometimes, although the whole cell stains deeply, granules cannot be distinguished. Dentate nucleus.—These cells in the carotene-deficient animals do not as a rule show such severe changes as the Purkinje cells, but loss of definition of the nucleus and powdery granules are often found. Other groups of cells (Plate IX, figs. 7 and 8).—Here are included the medial accessory olivary nucleus and cells scattered in the median raphe, especially in the medulla. Many cells showing the changes described above are seen, but intense chromolytic changes such as are found when the axon of a motor cell is cut were obvious in some cells. These are the cells, referred to on page 164 as exceptional in their reactions. Their appearance, in contrast with most other cells examined in this investigation, would suggest trauma of their conducting axon. Discussion. The foregoing account describes some of the changes in the central and peripheral nerve-fibres, and in the central and peripheral nerve-cells which can be readily produced in young rabbits by diets rich in cereals and deficient in carotene and vitamin A. Only the anatomical changes in relation to the general behaviour of the affected animals have been dealt with here. The experimental development of the study and its clinical significance I have discussed elsewhere [1 (a) (b) (c) (d) (e) (/)]. There [1 (c) (d) (/)] I have indicated a probable relationship between various diseases of the nervous system and diet which further work will no doubt expand. There is, for instance, good evidence that in some of the so-called toxic degenerations, especially those associated with restricted diets as convulsive ergotism, pellagra and lathyrism, a deficient intake of vitamin A and carotene is of eetiological significance. In sub¬ acute combined degeneration of the cord, the evidence is not so good, but it is difficult to escape the conclusion, not only that this disease is nutritional in origin, but that the responsible defect involves a biochemical mechanism in which vitamin A is concerned. Even in disseminated sclerosis there is suggestive evidence that a diet rich in vitamin A and other protective food factors increases the resistance of the nervous system to the toxic agent at fault, and that such a diet can improve the clinical condition of early acute attacks of this disease and possibly check the rate of advance in more established chronic cases. It is necessary to emphasize that the investigations here described