title: Graphic-digitizer analysis of axon spectra in ethmoidal and lingual branches of the trigeminal nerve.
abstract: Sections were removed from the lingual and ethmoidal nerves of cats and histologically prepared, and the fibers were analyzed under the light microscope. Neural dimensions were measured by a new technique, employing a graphic digitizer and computer. The outline of a neural structure was traced with the digitizer pen, and the total number of axons, their cross-sectional areas, shapes, diameter spectra, and locations within the nerve were calculated. Both nerves had unimodal axon spectra with the peak between 2 and 6 mum diameter. Differences in axon composition occurred over the diameter range of 9 to 20 mum; the lingual nerve had many axons in this range, the ethmoidal nerve only a few. The total number of myelinated axons was near 4000 in the lingual nerve, near 1400 in the ethmoidal nerve; only the latter had many large-sized Remak bundles (containing C-fibers). Most myelinated axons were not perfectly circular but exhibited various degrees of distortion.
mesh_terms: D000703:Analog-Digital Conversion; D000818:Animals; D001369:Axons / Q000502:physiology / Q000648:ultrastructure*; D002415:Cats; D002452:Cell Count; D008036:Lingual Nerve / Q000166:cytology; D009413:Nerve Fibers, Myelinated; D009431:Neural Conduction; D009882:Ophthalmic Nerve / Q000166:cytology; D010784:Photomicrography; D013329:Structure-Activity Relationship; D014276:Trigeminal Nerve / Q000166:cytology*