Studies on unmyelinated axons and varicosities in the olfactory cortex

1990 ◽  
Vol 80 (2) ◽  
Author(s):  
A. Gracey ◽  
C.N. Scholfield
Keyword(s):  
Olfactory Cortex ◽  
Unmyelinated Axons

Ultrastructure of Giant Mitochondria and Their Inclusions in Schwann Cells of Bovine Splenic Nerve

1974 ◽  
Vol 32 ◽  
pp. 194-195
Author(s):  
Å. Thureson-Klein
Keyword(s):  
Schwann Cells ◽  
Cell Organelles ◽  
Giant Mitochondria ◽  
Matrix Density ◽  
Physiological Conditions ◽  
Unmyelinated Axons ◽  
Internal Structures ◽  
Structural Abnormalities ◽  
Cytotoxic Compounds ◽  
Cell Components

Giant mitochondria of various shapes and with different internal structures and matrix density have been observed in a great number of tissues including nerves. In most instances, the presence of giant mitochondria has been associated with a known disease or with abnormal physiological conditions such as anoxia or exposure to cytotoxic compounds. In these cases degenerative changes occurred in other cell organelles and, therefore the giant mitochondria also were believed to be induced structural abnormalities.Schwann cells ensheating unmyelinated axons of bovine splenic nerve regularly contain giant mitochondria in addition to the conventional smaller type (Fig. 1). These nerves come from healthy inspected animals presumed not to have been exposed to noxious agents. As there are no drastic changes in the small mitochondria and because other cell components also appear reasonably well preserved, it is believed that the giant mitochondria are normally present jin vivo and have not formed as a post-mortem artifact.

High-voltage EM description of the types and distribution of sensory endings in the inner conical body of the rat vibrissal follicle-sinus complex

1990 ◽  
Vol 48 (3) ◽  
pp. 410-411
Author(s):  
Tony M. Mosconi ◽  
Min J. Song ◽  
Frank L. Rice
Keyword(s):  
Mammalian Species ◽  
Dorsal Side ◽  
Hair Shaft ◽  
Sensory Innervation ◽  
Conical Body ◽  
Adult Rats ◽  
Perpendicular Plane ◽  
Ultrastructural Studies ◽  
Unmyelinated Axons ◽  
Sensory Endings

Whiskers or vibrissal follicle-sinus complexes (F-SCs) on the snouts of many mammalian species are structures that have complex, dense sensory innervation. The innervation of F-SCs is remarkably similar in all species with the exception of one site - the inner conical body (ICB). The ICB is an elongated cylindrical structure that encircles the hair shaft near the neck of the follicle. This site has received only cursory attention in ultrastructural studies of the F-SCAdult rats were perfused after the method of Renehan and Munger2. F-SCs were quartered longitudinally and embedded separately in Epon-Araldite. Serial 0.25 μm sections were cut in either the longitudinal or perpendicular plane through the ICB and examined with an AEI EM7 1.2 MV HVEM (Albany, NY) at 1000 KV. Sensory endings were reconstructed from serial micrographs through at least 20 μm in the longitudinal plane and through 10 μm in the perpendicular plane.From two to six small superficial vibrissal nerves converge upon the neck of the F-SC and descend into the ICB. The nerves branch into smaller bundles of myelinated and unmyelinated axons along the dorsal side of the hair shaft.

Sign in / Sign up

Export Citation Format

Share Document