Abstract
A detailed histochemical study of the distribution of adenosine triphosphatase among trigeminal ganglion cells, associated nerves and epi-, peri-, and endoneurium has been carried out. The latter as well as the pericellular zones show the highest degree of the enzymatic activity. The intracellular activity, although feeble in most of the cases as compared to the pericellular zones, is revealed as morphological entities—as filamentous or vesicular bodies or solid clumps. These are sometimes arranged in the perinuclear zone, at other times as concentric rings in the middle part of the cytoplasm. They may be concentrated at the peripheral part or distributed as isolated bodies throughout the cytoplasm. It has been suggested that these bodies, distributed in various topographical fashions, represent the enzymatically active site of the endoplasmic reticulum. Further, a coordination of various stages seen among different cells, suggests that there is a shifting of the enzymatic activity from the perinuclear zone to the peripheral part of the cytoplasm. At the latter site and in the adjacent pericellular areas there is a strong possibility of an enzymatic role in the membrane permeability. The enzyme may also be playing such a role in epi-, peri- and endoneurium.