Relation between the number of myelin lamellae and axon circumference in fibers of vagus and sciatic nerves of mice

Friede, Reinhard L.; Samorajski, T.

doi:10.1002/cne.901300304

Cited by 231 publications

(71 citation statements)

References 21 publications

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“…But if cats 1, 3 and 4 are taken as typical, and cat 2 as having unusually thin myelin sheaths, then it may be concluded that g is about 0 70 for group III and small y fibres, falls to about 0-62 for group II and large y fibres and then rises again to 0-72 for group I and a fibres ( Fig. 10 and Table 2 Axon perimeter and number of myelin lamellae are linearly related for all sizes of axon in peripheral nerves in the mouse and rat (Friede & Samorajski, 1967, 1968, in rat ventral spinal roots (Fraher, 1972) and in central tracts in rat and cat (Samorajski & Friede, 1969;Bishop, Clare & Landau, 1971). There are few axons larger than 20 ,tm in perimeter in most mice and rats.…”

Section: Resultsmentioning

confidence: 96%

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Ultrastructural dimensions of myelinated peripheral nerve fibres in the cat and their relation to conduction velocity

Arbuthnott

Boyd

Kalu

1980

The Journal of Physiology

160

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SUMMARY1. The ultrastructure of all the afferent fibres, or all the efferent fibres, was studied in selected nerves from chronically de-afferentated or de-efferentated cat hind limbs perfusion-fixed with glutaraldehyde.2. The following parameters were measured: number of lamellae in the myelin sheath (n), axon perimeter (s), external fibre perimeter (S), axon cross-sectional area (A). Fibres were allocated to afferent groups I, II, III or efferent groups a and y according to the number of lamellae in the myelin sheath.3. of axon so that m = 2-58 log10 s -1t73. The interpretation that there are two separate linear relations for large and small fibres is favoured. 6. The ratio of axon to external fibre perimeter (g) falls from about 0 70 for group III and small y fibres in the cat to about 0-62 for group II and large y fibres and then rises again to 0'70, or even 0-75 for group I and a axons. (Hursh, 1939;Lubinska, 1960; Coppin, 1973) and between I and 0 (Coppin & Jack, 1972).8. From the theoretical analyses of Rushton (1951) and others 0 should be proportional to the external dimensions of the fibre rather than to axon size. It is shown

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Section: Resultsmentioning

confidence: 96%

“…A. BOYD AND K. U. KALU subdivision of fibres into groups. The number of myelin lamellae, however, is almost constant along an internode, and Friede & Samorajski (1967) suggested that it was a better criterion to employ. This has been done throughought this paper.…”

Section: Resultsmentioning

confidence: 99%

Ultrastructural dimensions of myelinated peripheral nerve fibres in the cat and their relation to conduction velocity

Arbuthnott

Boyd

Kalu

1980

The Journal of Physiology

160

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“…Another relevant aspect of axonal development is the determination of axonal caliber, which is influenced by intrinsic neuronal factors and extrinsic factors related to myelination (Friede and Samorajski, 1967). In fact, glial cells sense axonal diameter and from this information they determine whether an axon should be myelinated and the size of myelin sheath to synthesize.…”

Section: Mitochondria and Axonal Maturationmentioning

confidence: 99%

The Mitochondrial Protease AFG3L2 Is Essential for Axonal Development

Maltecca¹,

Aghaie²,

Schroeder³

et al. 2008

J. Neurosci.

122

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The mitochondrial metalloprotease AFG3L2 assembles with the homologous protein paraplegin to form a supracomplex in charge of the essential protein quality control within mitochondria. Mutations of paraplegin cause a specific axonal degeneration of the upper motoneuron and, therefore, hereditary spastic paraplegia. Here we present two Afg3l2 murine models: a newly developed null and a spontaneous mutant that we found carrier of a missense mutation. Contrasting with the mild and late onset axonal degeneration of paraplegin-deficient mouse, Afg3l2 models display a marked impairment of axonal development with delayed myelination and poor axonal radial growth leading to lethality at P16. The increased severity of the Afg3l2 mutants is explained by two main molecular features that differentiate AFG3L2 from paraplegin: its higher neuronal expression and its versatile ability to support both hetero-oligomerization and homo-oligomerization. Our data assign to AFG3L2 a crucial role by linking mitochondrial metabolism and axonal development. Moreover, we propose AFG3L2 as an excellent candidate for motoneuron and cerebellar diseases with early onset unknown etiology.

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“…In spite of the great utilization of morphometric techniques in neuropathy studies, this technique has proven extremely useful for the definition of normal parameters of nerves, either in humans (O'Sullivan & Swallow, 1968;Ochoa, 1971;Jacobs & Love, 1985) or in laboratory animals (Friede & Samorajski, 1967;Sato et al, 2006;Schiavoni & Fazan, 2006). Thus, data obtained with morphometry is used as the morphological basis for investigation of systemic and/or local diseases that compromise the peripheral nervous system.…”

Section: Discussionmentioning

confidence: 99%

Hind Limb Sensory Innervation in Rats: Comparison between Sural and Saphenous Nerve Morphometry

et al. 2015

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NERI, L. O.; DE AMORIM, M. M.; CAMPOS, S. A. R.; SANADA, L. S. & FAZAN, V. P. S. Hind limb sensory innervation in rats:Comparison between sural and saphenous nerve morphometry. Int. J. Morphol., 33(2):743-750, 2015. SUMMARY:Although numerous studies investigate sensory recovery of the hind paw of the rat after nerve damage, still no comprehensive overview of its normal innervation is present in the literature. We investigated the morphometry of myelinated fibers in the sural and saphenous nerves and analyzed their size distributions in young rats. Six 30-day-old female Wistar rats were perfused with 2.5% glutaraldehyde and their right and left sural and saphenous nerves were prepared for light microscopy and morphometry. Morphometric data were compared between segments (proximal versus distal) and sides (right versus left) for the same nerves. Also, segments from right or left sides were compared between nerves (sural versus saphenous). Both, the sural and saphenous nerves, exhibited proximal to distal symmetry on both sides as well as left-right symmetry. Histograms of the diameter of the myelinated fibers were unimodal in both nerves, regardless of segments or sides with the peaks of the fibers size occurring between 2.5 and 4.0 µm. The axon distributions reflected the myelinated fiber distributions, with the sural and saphenous nerves peaking between 1.5 and 2.0 µm. The G ratio (the ratio between the axon and fiber diameters) distributions were also unimodal, with peaks at 0.6 for both nerves. This study contributes to the literature with information on the myelinated fibers morphometry from the two sensory nerves responsible for the rat hind limb innervation. This information is valuable for a better understanding of the possible contribution of collateral sprouting from the sural or saphenous nerves on the paw sensory territory recovery observed after one of these nerves is damaged.

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Relation between the number of myelin lamellae and axon circumference in fibers of vagus and sciatic nerves of mice

Cited by 231 publications

References 21 publications

Ultrastructural dimensions of myelinated peripheral nerve fibres in the cat and their relation to conduction velocity

Ultrastructural dimensions of myelinated peripheral nerve fibres in the cat and their relation to conduction velocity

The Mitochondrial Protease AFG3L2 Is Essential for Axonal Development

Hind Limb Sensory Innervation in Rats: Comparison between Sural and Saphenous Nerve Morphometry

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