Histochemical localization of carbonic anhydrase in vertebrate nervous tissue

Abstract

The histochemical method of Häusler was employed to demonstrate carbonic anhydrase (CA, carbonate hydrolase, 4.2.1.1.) in tissue sections. The CA reaction was inhibited in the presence of 5 mM acetazolamide. In the frog and fish retinas the CA activity was positive in the Müller fiber, the laminated segment of the cones and the myelin of the axons, and was negative in the laminated segment of the rods, the photoreceptor ellipsoid and myoid, the horizontal, bipolar, amacrine and ganglion cells, and the pigment epithelium. In the spinal cord of cat and fish the CA activity was positive in the myelin of the axons, the perineuronal oligodendroglia and the protoplasmic astrocytes, and was negative in the cell body, dendrite, and axon of the neurons and in the fibrous astrocytes. In the dorsal root ganglion of the cat CA reaction was positive in the satellite cells and the myelin, and was negative in the neuronal cell body and its processes. The capillaries in central nervous tissue show no CA reaction. The erythrocyte is CA positive while the mitochondria are CA negative.

Biochemical subtypes of oligodendrocyte in the anterior medullary velum of the rat as revealed by the monoclonal antibody rip

“…However, CAII has been confirmed to be oligodendrocyte specific in white matter by in situ hybridization (Ghandour and Skoff, 1991) and our results indicated that in the AMV CAII specifically recognized oligodendrocytes. This localization of CAII in oligodendrocytes and their myelin sheaths has led to the belief that it is intimately involved in myelination Cammer et al, 1976Cammer et al, ,1977Ghandour and Skoff, 1991;Ghandour et al, 1979Ghandour et al, ,1980Parthe, 1981;Roussel et al, 1979;Sapirstein and Lees, 1977;Sapirstein et al, 1978;Snyder et al, 1983;Yandrasitz et al, 1976). In most cells, carbonic anhydrase is involved in cellular pH regulation and fluid and ion movements (Maren, 1984).…”

Ionic and acid-base regulation of neurons and glia during seizures

“…Cytochemical as well as histochemical studies indicate that CA is almost exclusively present in glial elements, both oligodendrocytes and astrocytes 11,[7][8][9][10][11][12]17, 201 (Anderson RE, Woodbury DM: unpublished observations, 1983). The enzyme promotes the hydration of C 0 2 to carbonic acid (H2C03), which spontaneously dissociates into H+ and HC03-, or at high pH:…”

Synchronised Paroxysmal Ocular Tilt Reaction and Limb Dystonia

“…38,39 Acetazolamide acts on neurons and glial cells, but is unlikely to interrupt ephaptic transmission because there is no membrane bound carbonic anhydrase on axons. 40,41 The mechanism is probably related to pH changes at the dendritic level. 42…”