Quantitative analysis of the optic nerve of the horse (Thoroughbred).
Abstract: Three optic nerves (L1, R2, R3) 12-18 mm behind the eyeball of the horse (Thoroughbred) were investigated quantitatively under light and electron microscopes. Thin sections at the thickness of 0.35 microm were cut, stained by toluidine blue and observed under the light microscope. The areas of the optic nerve and the axon bundles were 20.03 +/- 1.04 and 16.59 +/- 0.79 mm2 (mean +/- SD, n=3), respectively. The axon numbers for optic nerve L1, R2 and R3, estimated from light micrographs, were about 481 x 10(3), 543 x 10(3), and 494 x 10(3), respectively. Axons of optic nerve L1 were also counted from electron micrographs and the total number of 488 x 10(3) was received. Furthemore, axon diameters of optic nerve L1 were also measured from electron micrographs. The diameter of a circle with the same peripheral length as an axon, was regarded as its diameter. The medullary sheath of the axon was not included during measuring. Altogether 5,744 axons were measured and axon diameters were in a range of 0.23-12.69 microm, with a mean of 2.56 +/- 1.45 microm (mean +/- SD). A regional difference of axonal diameters was found across the optic nerve: the mean diameter of axons in the centrodorsal region (2.28 microm) was the smallest, and had significant difference with those in several peripheral regions (P<0.05).
Publication Date: 2001-10-20 PubMed ID: 11642285DOI: 10.1292/jvms.63.971Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This research study involves a quantitative analysis of the <a href="/equine-cranial-nerve-anatomy/" title="<a href="/equine-cranial-nerve-anatomy/" title="Cranial Nerves in Horses: Role in Sight, Hearing, Chewing & Balance”>Cranial Nerves in Horses: Role in Sight, Hearing, Chewing & Balance”>optic nerve of a Thoroughbred horse. Through the use of light and electron microscopes, the study provides detailed measurements and counts of axon quantities and diameters, revealing evident regional variations in the axon diameter across the optic nerve.
Methodology
- The research was carried out on three optic nerves (L1, R2, R3) from a Thoroughbred horse, located 12-18 mm behind the eyeball.
- The nerves were analyzed quantitatively under light and electron microscopes.
- Thin sections of 0.35 microm were cut, stained with toluidine blue, and then examined under the light microscope.
Findings
- The sizes of the optic nerve and the axon bundles were found to be 20.03 +/- 1.04 and 16.59 +/- 0.79 mm2 (mean +/- SD, n=3), respectively.
- The axon numbers for optic nerves L1, R2, and R3, estimated from light micrographs, were approximately 481 x 10(3), 543 x 10(3), and 494 x 10(3), respectively.
- Further examination of optic nerve L1 under an electron microscope provided an estimated axon count of 488 x 10(3).
- In addition, the diameter of axons from optic nerve L1 was measured from the electron micrographs. The peripheral length of an axon was determined to be equivalent to the diameter of a circle, excluding the medullary sheath of the axon during measurement.
- A total of 5,744 axons were measured, with axon diameters ranging between 0.23-12.69 microm, and a mean diameter of 2.56 +/- 1.45 microm.
Significance
- The research observed a significant regional difference in axonal diameters across the optic nerve.
- Specially, the mean diameter of axons in the centrodorsal region (2.28 microm) was the smallest, and was statistically significantly different from those in several peripheral regions (P<0.05).
Cite This Article
APA
Guo X, Aoyama M, Sugita S.
(2001).
Quantitative analysis of the optic nerve of the horse (Thoroughbred).
J Vet Med Sci, 63(9), 971-975.
https://doi.org/10.1292/jvms.63.971 Publication
Researcher Affiliations
- Department of Animal Science, Faculty of Agriculture, Utsunomiya University, Japan.
MeSH Terms
- Animals
- Axons / ultrastructure
- Horses / anatomy & histology
- Microscopy, Electron / veterinary
- Optic Nerve / anatomy & histology
- Optic Nerve / ultrastructure
Citations
This article has been cited 2 times.- Liewald D, Miller R, Logothetis N, Wagner HJ, Schüz A. Distribution of axon diameters in cortical white matter: an electron-microscopic study on three human brains and a macaque. Biol Cybern 2014 Oct;108(5):541-57.
- Wang SS, Shultz JR, Burish MJ, Harrison KH, Hof PR, Towns LC, Wagers MW, Wyatt KD. Functional trade-offs in white matter axonal scaling. J Neurosci 2008 Apr 9;28(15):4047-56.
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