Distribution, size and number of axons in the optic pathway of ground squirrels

Experimental Brain Research
P T JohnsonB E Reese

Abstract

The present study has examined the distribution of axons of differing sizes in the optic pathway of the ground squirrel. Axon diameters were measured from electron micrographs at various locations across sections of the optic nerve and tract, and total distributions and numbers were estimated. In both the nerve and tract, roughly 1.2 million optic axons were present. The population of optic axons had a unimodal size distribution, peaking at 0.9 microm in diameter and having an extended tail toward larger diameters. Local axon diameter distributions in the optic tract indicated distinct (though partially overlapping) axon diameter classes, including one of fine sizes peaking at 0.8-0.9 microm, a second of medium sizes peaking around 1.7-1.8 microm, and a third composed of the larger fibers with diameters up to 4.8 microm. The fine-caliber axons were found at all locations in the tract, and were the only axons present immediately adjacent to the pia, while the medium- and coarse-caliber axons were found at deeper locations. Curiously, the larger axons were found primarily in the medial parts of the tract, where axons from the dorsal retina normally course. A similarly restricted distribution of the larger axons was observed in th...Continue Reading

Citations

Nov 7, 2000·Magnetic Resonance in Medicine : Official Journal of the Society of Magnetic Resonance in Medicine·Y AssafY Cohen
Oct 6, 2006·Visual Neuroscience·Stephen D Van Hooser, Sacha B Nelson
Jun 9, 2001·Veterinary Ophthalmology·D.E. BrooksM.E. Källberg
Jan 26, 2016·Experimental Eye Research·Dana K MerrimanBryan W Jones
Apr 20, 2004·Veterinary Ophthalmology·Lindsay A KuesterMae Chisholm
Mar 28, 2006·Journal of Human Evolution·E Christopher Kirk
Feb 11, 2009·Magnetic Resonance in Medicine : Official Journal of the Society of Magnetic Resonance in Medicine·T WeberP M Jakob
Jul 1, 2020·Seminars in Cell & Developmental Biology·Wei Li
Jul 14, 2021·Laboratory Investigation; a Journal of Technical Methods and Pathology·Xuan XiaoFrancisco M Nadal-Nicolás

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