oligodendro.site Home cyto.site Go Premium

Myelin budget twin

oligodendrocyte, alive: the cell keeps working while you watch. Every motion runs at a rate from a source, and the panel below drives it.

This stage needs the page's JavaScript, and it has not arrived. If this line stays, the page was served but its script was not: reload, and if it persists the dev server's dependency cache is stale.

Control panel

One oligodendrocyte, its internodes as geometry: move a slider and the sheath, the budget and the readouts follow.

Total myelin sheath volume

46,042 um3

7.46 to 2,714,336 um3 across the sourced ranges. No sourced capacity for this quantity, so the bar places this cell between the smallest and the largest the sourced ranges allow, on a log scale.

Exact geometry: each internode is a hollow cylinder between the axon (g-ratio times fibre diameter) and the fibre surface. This is the quantity the cell must build and maintain; it is the twin's budget.

source 1source 2,

Side viewCross sectioninternode 300 umnodex1, drawn wider than scalefibre 4 umaxon 3.08 um, g-ratio 0.77Lengths and diameters are drawn at different scales; the node is widened so it stays visible.

Inputs

1 to 50 · mouse and human, review · review · Nave KA and Werner HB 2014, Annu Rev Cell Dev Biol · source

a single oligodendrocyte supports up to about 50 internodes

1 to 12 um · rat, adult anterior medullary velum · light microscopy of teased fibres · Ibrahim M, Butt AM, Berry M 1995, J Neurol Sci · source

myelin sheath external diameters under 1 to 12 um

50 to 750 um · rat, adult anterior medullary velum · light microscopy of teased fibres · Ibrahim M, Butt AM, Berry M 1995, J Neurol Sci · source

internodal lengths 50 to 750 um, broadly linear with sheath diameter; sheaths under 4 um have shorter internodes than the line predicts

0.6 to 0.9 · rat CNS, theory · biophysical model · Chomiak T and Hu B 2009, PLoS One · source

optimal CNS g-ratio about 0.77; about 0.6 in some peripheral fibres (Rushton 1951, https://pubmed.ncbi.nlm.nih.gov/14889433/)

0.5 to 4.4 x · rat optic nerve and cortex · electron microscopy and modelling · Arancibia-Carcamo IL et al. 2017, eLife · source

node length varies 4.4-fold in optic nerve and 8.7-fold in cortex; the slider covers the optic nerve range around a typical node

17 to 18.2 nm · rat brain · molecular X-ray computed tomography · Jensen TH et al. 2011, NeuroImage · source

periodicity of the myelin sheaths 17.0 to 18.2 nm around an average of 17.6 nm

0 to 1 Hz · rabbit, awake, antidromic identification · extracellular single-unit recording · Swadlow HA 1994, J Neurophysiol; also 1991 PMID 1761989 and 1990 PMID 2358887 · source

callosal and thin corticocortical axons (diameter < 2 um): mean firing rate < 1 spike/s; range 0-1 Hz in the sources

1 to 6 Hz · rabbit, awake, antidromic identification · extracellular single-unit recording · Swadlow HA 1994, J Neurophysiol; also 1991 PMID 1761989 and 1990 PMID 2358887 · source

corticofugal layer 5 axons (diameter >= 2 um): mean 4.1-5.7 spikes/s across the Swadlow 1990/1991/1994 studies; range 1-6 Hz

Readouts

Axon diameter
3.08 um
3.08 to 3.08 um exact
definition · g-ratio definition  · source 1
Exact given inputs.
Sheath thickness
0.46 um
0.46 to 0.46 um exact
definition · geometry  · source 1
Exact given inputs.
Sheath volume, one internode
1,535 um3
7.46 to 54,287 um3 propagated
rat · geometry on measured ranges  · source 1
Interval from evaluating at the ends of each input range; assumes the formula moves one way in each input.
Outer sheath surface, all internodes
113,097 um2
157 to 1,413,717 um2 propagated
rat, mouse and human · geometry on measured ranges  · source 1 · source 2
Interval from evaluating at the ends of each input range; assumes the formula moves one way in each input.
Axon length myelinated by this cell
9,000 um
50 to 37,500 um propagated
rat, mouse and human · geometry on measured ranges  · source 1 · source 2
Interval from evaluating at the ends of each input range; assumes the formula moves one way in each input.
Number of lamellae (wraps)
26.1
2.75 to 141 propagated
rat · sheath thickness divided by the X-ray period  · source 1 · source 2
Interval from evaluating at the ends of each input range; assumes the formula moves one way in each input.
Myelin membrane area, all internodes
2,616,018 um2
410 to 1.60e8 um2 propagated
rat, mouse and human · wraps times the mean circumference times length; each wrap is a flattened tongue of two bilayers, both faces counted  · source 1 · source 2 · source 3
Interval from evaluating at the ends of each input range; assumes the formula moves one way in each input.
Conduction velocity
24 m/s
6 to 72 m/s propagated
macaque pyramidal tract · Firmin 2014: 1 um fibres (with sheath) at 6 m/s and 3 um at 18 m/s in the macaque pyramidal tract, an empirical slope of 6 m/s per um, not an identity; Waxman 1980: velocity nearly proportional to diameter  · source 1 · source 2
Interval from evaluating at the ends of each input range; assumes the formula moves one way in each input.
Conduction change from node length
0 percent
-20 to 20 percent reported
rat, model · Arancibia-Carcamo 2017: node length differences alter conduction speed by about 20 percent across the observed range; scaled linearly here  · source 1
Interval reported in the source, not computed here.
Membrane needed at the node versus the sheath
270 fold less
270 to 270 fold less reported
rat, model · for a given conduction change, more than 270-fold less membrane at the node than in the sheath  · source 1
Interval reported in the source, not computed here.

Sources

Nave KA, Werner HB. Myelination of the nervous system: mechanisms and functions. Annu Rev Cell Dev Biol 2014
review · review
Ibrahim M, Butt AM, Berry M. Relationship between myelin sheath diameter and internodal length. J Neurol Sci 1995
rat · light microscopy of teased fibres
Chomiak T, Hu B. What is the optimal value of the g-ratio for myelinated fibers in the rat CNS? PLoS One 2009
rat, theory · biophysical model
Rushton WA. A theory of the effects of fibre size in medullated nerve. J Physiol 1951
theory · theory
Waxman SG. Determinants of conduction velocity in myelinated nerve fibers. Muscle Nerve 1980
review · review
Arancibia-Carcamo IL et al. Node of Ranvier length as a potential regulator of myelinated axon conduction speed. eLife 2017
rat · electron microscopy and modelling
Agrawal D et al. Internodal myelination during development quantitated using X-ray diffraction. J Struct Biol 2009
mouse · X-ray diffraction
Hildebrand C, Hahn R. Relation between myelin sheath thickness and axon size in spinal cord white matter. J Neurol Sci 1978
several vertebrates · electron microscopy
Jensen TH et al. Molecular X-ray computed tomography of myelin in a rat brain. NeuroImage 2011
rat brain · small-angle X-ray scattering computed tomography (SAXS-CT), intact tissue
Firmin L et al. Axon diameters and conduction velocities in the macaque pyramidal tract. J Neurophysiol 2014
macaque, corticospinal tract · antidromic latency electrophysiology and electron microscopy morphometry
Jensen TH et al. Molecular X-ray computed tomography of myelin in a rat brain. NeuroImage 2011
rat · X-ray computed tomography
Firmin L et al. Axon diameters and conduction velocities in the macaque pyramidal tract. J Neurophysiol 2014
macaque · electrophysiology and electron microscopy

Research use only. Every number here is geometry on published ranges, not a measurement of any individual.

Substances tested 14

All substances →
Clemastine fumarate antihistamine with antimuscarinic action
acts on muscarinic receptors (M1 and M3)
Promotes oligodendrocyte precursor differentiation and remyelination. In the ReBUILD crossover trial the primary endpoint was met: visual evoked potential latency delay reduced by 1.7 ms per eye (95% CI 0.5 to 2.9, p = 0.0048); fatigue was associated, no serious adverse events.
dose: trial dose not stated in the abstract  · human, 50 patients with multiple sclerosis  · randomised double-blind placebo-controlled crossover trial, 150 days  · Green AJ et al. 2017, Lancet  · source
Clemastine antihistamine with antimuscarinic action
acts on muscarinic receptors, ERK1/2, Myrf and Olig2
Promotes OPC differentiation through muscarinic receptors and ERK1/2 activation with increased Myrf and Olig2; blocked by ERK inhibition (U0126) and reduced by the muscarinic agonist cevimeline.
dose: not stated in the abstract  · rat, spinal cord injury  · in vivo pharmacology  · Tong LY et al. 2022, Front Pharmacol  · source
Antimuscarinic compounds (screen) muscarinic antagonists
acts on muscarinic receptors
Screening 1,000 bioactive molecules on micropillar arrays identified a cluster of antimuscarinic compounds that enhance oligodendrocyte differentiation and remyelination.
dose: screen concentrations not stated in the abstract  · rodent OPCs in vitro (species not stated in the abstract)  · high-throughput micropillar screen  · Mei F et al. 2014, Nat Med  · source
Benztropine anticholinergic
acts on direct antagonism of M1 and/or M3 muscarinic receptors
Among the most effective compounds in an image-based screen for myelin basic protein expression; decreases clinical severity in EAE alone or with approved immunosuppressants; efficacy from enhanced remyelination, not immune suppression (cuprizone model, T-cell assays).
dose: not stated in the abstract  · rat optic nerve OPCs in vitro; mouse EAE and cuprizone models  · screen plus in vivo models  · Deshmukh VA et al. 2013, Nature  · source
Miconazole antifungal
acts on mitogen-activated protein kinase signalling in OPCs
Increases new oligodendrocytes and enhances remyelination in lysolecithin lesions; reverses disease severity at the peak of EAE; acts directly as a remyelinating drug with no immune effect; enhances human oligodendrocyte generation from human OPCs in vitro.
dose: not stated in the abstract  · mouse; human cells in vitro  · in vivo lesion models and in vitro  · Najm FJ et al. 2015, Nature  · source
Clobetasol glucocorticoid
acts on glucocorticoid receptor signalling in OPCs
Same remyelinating effects as miconazole in lysolecithin and EAE models, and a potent immunosuppressant as well; enhances human oligodendrocyte generation in vitro.
dose: not stated in the abstract  · mouse; human cells in vitro  · in vivo lesion models and in vitro  · Najm FJ et al. 2015, Nature  · source
Metformin antidiabetic
acts on aged OPCs (mechanism beyond the abstract not claimed here)
Restores CNS remyelination capacity by rejuvenating aged OPCs, which had become unresponsive to pro-differentiation signals.
dose: not stated in the abstract  · aged rodents  · in vivo  · Neumann B et al. 2019, Cell Stem Cell  · source
Opicinumab anti-LINGO-1 monoclonal antibody
acts on LINGO-1
In acute optic neuritis (RENEW), the visual evoked potential latency benefit over placebo was greatest in participants aged 33 or older (-14.17 ms, p = 0.01) and absent below 33 (-0.89 ms, p = 0.87); latency recovery associated with less retinal ganglion cell layer thinning.
dose: not stated in the abstract  · human, 33 treated and 36 placebo  · randomised trial, per-protocol analysis  · Cadavid D et al. 2018, Ann Clin Transl Neurol  · source

Every row rests on a PubMed abstract read in full by golden.goose on 2026-09-12; a dose not stated in the abstract is written as such, never guessed. Research reference, not medical advice.

Public datasets 4

GSE75330 single-cell RNA-seq Mus musculus
RNA-seq analysis of single cells of the oligodendrocyte lineage from nine distinct regions of the anterior-posterior and dorsal-ventral axis of the mouse juvenile central nervous system
Marques S et al. 2016, Science  · paper  · public at NCBI GEO; NCBI data are free to use with attribution, no licence text of its own  · accession resolved 2026-09-12 via eutils esummary
GSE118257 single-nucleus RNA-seq Homo sapiens
Altered oligodendrocyte heterogeneity in Multiple sclerosis.
Jakel S et al. 2019, Nature  · paper  · public at NCBI GEO  · accession resolved 2026-09-12 via eutils esummary
GSE67835 single-cell RNA-seq Homo sapiens
A survey of human brain transcriptome diversity at the single cell level
Darmanis S et al. 2015, PNAS (title checked)  · paper  · public at NCBI GEO  · accession resolved 2026-09-12 via eutils esummary
mousebrain.org single-cell RNA-seq atlas Mus musculus
Molecular Architecture of the Mouse Nervous System (atlas site)
Zeisel A et al. 2018, Cell  · paper  · site answered (301 to its current address); data terms to be read on the site before reuse  · accession resolved 2026-09-12

Public datasets on the oligodendrocyte lineage. Every GEO accession resolved through NCBI eutils on the date shown; the series title is the one GEO returns, not a paraphrase.