Mucopolysaccharides in the dog spinal cord and dorsal root ganglia

Abstract

A histochemical study of mucopolysaccharides in the dog spinal cord and dorsal root ganglia is reported in this paper. The histochemical techniques used were the following: PAS, colloidal iron, toluidine blue (pH 5.4 and 3.5), thionine (pH 5.4 and 3.5) and alcian blue 8GX (pH 1 and 2.5). Some histological stains were used also. Two types of neurons could be observed in spinal cord sections stained with colloidal iron techniques. In some neuron a border line of mucosubstances could be seen. In the dorsal root ganglia, different patterns of Nissl bodies distribution in neurons were described. This different distribution of Nissl bodies is associated with different metachromatic colorations of neurons. By using the colloidal iron method, two types of neurons were also revealed in the dorsal root ganglia: some neurons are of a yellow, small-sized and star-shaped type and others are of a light green, larger and round-shaped type. Mucosubstances in the endoneurium and perineurium of nerve fibers, in the Ranvier nodules and in the Schmidt-Lantermann incisures were observed. The possibility that the functional rhythm in some cases might be responsible for the difference in coloration between the dorsal root ganglia neurons is suggested.

Histochemical study of the myelin-associated carbohydrates

“…The surface of myelin is positive for col loidal iron [García-Segura el al., 1976], PAS [Rodriguez-Pérez, 1956;García-Segura et al, 1977] and alcian blue 8GX [García-Segura et al, 1977]. Likewise, Ranvier nodes presented positivity when these staining methods and other ions were used [Garcia-Segura et al, 1976, 1977Quick and Waxman, 1977], Al though differences in the protein composition between myelin of the peripheral nervous system and that of the central nervous system have been described, and even quantitative differences between diverse nerves and be tween the same nerve of different species have also been reported [Greenfield et al, 1973], there are no great differences in the positivity of the myelin surface, obtained with the col loidal iron technique, between the peripheral nervous system and the central nervous sys tem.…”