Histochemical Studies on Distribution of Dephosphorylating and Oxidative Enzymes and Esterases in Olfactory Bulb of the Squirrel Monkey

Summary

Detailed histochemical studies on the localization of various groups of dephosphorylating and oxidative enzymes and esterases were made in the olfactory bulb of the squirrel monkey. These studies indicated that the nerve fiber layer had considerable activity for simple esterase and was moderately positive for most of the enzymes except thiamine pyrophosphatase and glucose-6-phosphatase. The olfactory glomeruli also gave a positive activity for most enzymes except thiamine pyrophosphatase. It was especially strongly positive for oxidative enzymes, adenosinetriphosphatase, alkaline phosphatase, monoamine oxidasc, and specific cholinesterase. It did not contain any thiamine pyrophosphatase-positive Golgi material. The mitral, tufted, and granule cells had moderately strong positive activity for all the enzymes, except alkaline phosphatase, glucose-6-phosphatase, and specific and nonspecific cholin esterases. The cell processes of the mitral and tufted cells were more strongly positive than the perikaryon itself. The periglomerular neuroglial cells gave positive activity for most enzymes, except specific and nonspecific cholinesterase and glucose-6-phosphatase. They were strongly positive for lactic dehy-drogenase and simple esterases. The external and internal plexiform layers showed identical enzyme distribution except for specific cholinesterase, which was present in the internal plexiform layer and negative in the external plexiform layer except for small fiber showing the positive activity here and there. In general, the external plexiform layer was more active than the internal plexiform layer. Histochemically, the olfactory glomeruli and cerebellar glomeruli in the granular layer showed identical enzyme distribution. The significance of these studies is described.