Summary
Axon caliber and myelin sheath thickness of individual nerve fibers were evaluated in the developing human sural nerve using three different methods of measurement: 1. ocular micrometer evaluation of large fibers, 2. photographic enlargements for evaluating large numbers of nerve fibers of all sizes, and 3. electron microscopic enlargements for more precise measurements in selected nerves. the average axonal diameter doubles from 5 months gestation to about 5 years of age. Large fiber group axons increase, during the same period, by a factor of 3–3.5 with a slight decrease thereafter. The myelin thickness increases more slowly, but continuously, between 5 months gestation until the age of 14. This asynchronous development of axons and myelin sheaths results in a statistically significant change of the ratio between axonal caliber and myelin thickness. The slope of the regression line is steeper in older than in younger individuals, and the correlation coefficient increases during development of the nerve.
Similar content being viewed by others
References
Buchthal, F., Rosenfalck, A.: Evoked action potentials and conduction velocity in human sensory nerves. Brain3, 1–122 (1966)
Cottrell, L.: Histologic variations with age in apparently normal peripheral nerve trunks. Arch. Neurol. Psychiat. (Chic.)43, 1138–1150 (1940)
Dyck, P. J., Lambert, E. H., Sanders, K., O'Brien, P. C.: Severe hypomyelination and marked abnormality of conduction in Dejerine-Sottas hypertrophic neuropathy: myelin thickness and compound action potential of sural nerve in vitro. Mayo Clin. Proc.46, 432–436 (1971)
Evans, D. H. L., Vizoso, A.D.: Observations on the mode of growth of motor nerve fibers in rabbits during postnatal development. J. Comp. Neurol.95, 429–461 (1951)
Fraher, J. P.: A quantitative study of anterior root fibres during early myelination. J. Anat. (Lond.)112, 99–124 (1972)
Friede, R. L., Samorajski, T.: Relation between number of myelin lamellae and axon circumference in fibers of vagus and sciatic nerves of mice. J. Comp. Neur.130, 223–232 (1967)
Friede, R. L., Samorajski, T.: Myelin formation in the sciatic nerve of the rat. A quantitative electron microscopic, histochemical and radioautographic study. J. Neuropath. Exp. Neuro.27, 546–570 (1968)
Gamstorp, I.: Normal conduction velocity of ulnar, median and peroneal nerves in infancy, childhood and abolescence. Acta paediat. Suppl.146, 68–76 (1963)
Gutrecht, J. A., Dyck, P. J.: Quantitative teased fiber and histologic studies of human sural nerve during postnatal development. J. Comp. Neurol.138, 117–130 (1970)
Ochoa, J.: The sural nerve of the human foets: electron microscope observations and counts of axons. J. Anat.108, 231–245 (1971)
Rexed, B.: Contributions to the knowledge of the postnatal development of the peripheral nervous system in man. Acta Psychiatr. Neurol. Suppl.33, 1–204 (1944)
Sanders, F. K.: The thickness of the myelin sheaths of normal and regenerating peripheral nerve fibres. Proc. Roy. Soc. Lond. Sci. B135, 323–357 (1948)
Schnepp, P., Schnepp, G.: Faseranalytische Untersuchungen an peripheren Nerven bei Tieren verschiedener Größe. II. Verhältnis Axondurchmesser/Gesamtdurchmesser und Internodallänge. Z. Zellforsch.119, 99–114 (1971)
Schröder, J. M.: Altered ratio between axon diameter and myelin sheath thickness in regenerated nerve fibers. Brain Res.45, 49–65 (1972)
Schröder, J. M.: Two-Dimensional reconstruction of Schwann cell changes following remyelination of regenerated nerve fibers. In: Proceedings of the symposium on structure and function of normal and diseased muscle and peripheral nerve, in Kazimierz upon vistula, Poland, May 18.–20. 1972 Eds.: I. Hausmanowa-Petrusewicz and H. Jedrzejowska, pp. 299–304. Warsaw: Pollsh Medical Publishers 1974
Sehröder, J. M.: Quantitative evaluation of regenerated nerve fibers. In: Studies on neuromuscular diseases, proceedings of the investigations in the clinics of neuromuscular diseases, Gießen, April 8–10, 1973, Eds.: K. Kunze, J. E. Desmedt, pp. 206–210. Basel: Karger 1975
Schwarzacher, H. G.: Markscheidendicke und Achsenzylinderdurchmesser in peripheren menschlichen Nerven. Acta anat. (Basel)21, 25–46 (1954)
Sunderland, S., Roche, A. F.: Axon-myelin relationship in peripheral nerve fibres. Acta anat.33, 1–37 (1958)
Thomas, P. K.: Growth changes in the diameter of peripheral nerve fibres in fishes. J. Anat.90, 5–14 (1956)
Thomas, J. E., Lambert, E. H.: Ulnar nerve conduction velocity and H-reflex in infants and children. J. appl. Physiol.15, 1–9 (1960)
Tohgi, H., Tsukagoshi, H., Toyokura, Y.: Quantitative changes with age in normal sural nerves. Acta neuropath. (Ber.)38, 213–220 (1970)
Williams, P. L., Wendell-Smith, C. P.: Some additional parametric variations between peripheral nerve fibre populations. J. Anat. (Lond.)109, 505–526 (1971)
Author information
Authors and Affiliations
Additional information
Supported in part by the Deutsche Forschungsgemeinschaft, Bonn-BadGodesberg, Federal Republic of Germany (Schr 195/3)
Rights and permissions
About this article
Cite this article
Schröder, J.M., Bohl, J. & Brodda, K. Changes of the ratio between myelin thickness and axon diameter in the human developing sural nerve. Acta Neuropathol 43, 169–178 (1978). https://doi.org/10.1007/BF00685012
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00685012