PHOSPHATASE HISTOCHEMISTRY OF FELINE CERVICAL SPINAL CORD AFTER BRACHIAL PLEXECTOMY

Abstract

A reticulum is demonstrable in perikaryon and dendrites of feline motoneurons by application of a histochemical technic for TPPase and NDPase activities. At the level of light microscopy this reticulum is separable from the basophil network of Nissl except that, in dendrites especially, lamellae derived from both structures appear, occasionally, to be in continuity or even identical. During axonal reaction the TPPase-, NDPase-positive reticulum recedes from the perinuclear area, especially opposite the axon, and migrates to the periphery. These changes, well-developed in the 15 to 30 day postoperative period, are followed by a restitution toward the normal appearance about 46 to 60 days after neurectomy. Regeneration of the reticulum appears to occur from both the cytoplasmic and nuclear membrane sides of the cytoplasm. The alternations encountered resemble those reported by earlier workers who applied classical technics for the Golgi apparatus to chromatolytic neurons. The network demonstrated by the enzyme histochemical method is equated with the Golgi organelle. Lysosomes, identified in Gomori acid phosphatase preparations, increase in numbers in chromatolytic neurons. In addition to the perikaryon, dendrites show a conspicuous increase in lysosomal content. This phenomenon is discussed. Possible developmental relations between lysosomes and other cell constituents are also discussed. Evidence, suggestive of a discharge of TPPAse- and NDPase-positive lamellae and lysosomes into axons during chromatolysis, is described. In TPPase and NDPase preparations there is a striking increase in glial activity in the anterior and posterior horns following plexectomy.