Avitaminosis. XVIII. Peripheral Nerves in Vitamin B 1 Deficiency as Observed by Polarized Light. ∗

Abstract

Although the literature is full of reports on nerve degeneration in avian polyneuritis and B deficiency in the rat and other mammals, the most recent contributions in this field reveal conflicting evidence. 1 In order to circumvent uncertainties in the interpretation of Marchi preparations and any possible artefacts that may be introduced during fixation and staining, Sutton, Setterfield and Krauss 2 have recently applied the polarized light technique for the study of degeneration of myelinated nerves in vitamin A deficiency. This technique was found by Setterfield and Baird 3 to have advantages over the Marchi method of staining with osmic acid, since it does not depend upon fixation and staining but on the chemical structure of the myelin sheath; moreover, it is more rapid, more sensitive and constant.

The polarized light technique, however, as employed by Sutton and associates requires previous fixation of tissues in formalin, which procedure may introduce artefacts. We have applied the technique of Sutton and co-workers in studies of vitamin B deficiency and have checked the formalin procedure by elimination of all fixatives as well as all staining operations. Small pieces of spinal cord, trigeminal, sciatic and optic nerves from avitaminotic and litter mate controls on the same plane of nutrition, were fixed in 95% alcohol in liquid air, and dehydrated in vacuo, at −32°C., by the Altmann-Gersh-freezing-drying technique, as modified by Scott and Williams. 4 Frozen sections were made and compared under polarized light with those fixed in 10% formalin. Twelve groups of rats were used for this comparative study. The pathological animals of 9 groups were on diets deficient only in vitamin B₁ and had varying degrees of polyneuritis, ranging from slight to marked paralysis.