Totada R. Shantha

Histological and histochemical observations on the capsule of the muscle spindle in normal and denervated muscle

Histological and histochemical studies of dephosphorylating enzyme distribution in muscle spindle capsule of guinea pig thigh muscles and cat calf muscles

Histochemical detection of l-gulonolactone: phenazine methosulfate oxidoreductase activity in several mammals with special reference to synthesis of vitamin C in primates

SummaryAn improved detection of activity of l-gulonolactone oxidase, which is responsible for the final oxidative step in the synthetic process of l-ascorbate from glucose in animals, was achieved using phenazine methosulfate and cyanide. Cold acetone fixation eliminated non-specific deposition of formazan on lipid droplets. The specificity of the method was tested and proven by a biological control, histochemical controls, inhibitors and activators. By application of the method, strong reactivity was found in the cytoplasm of centrilobular parenchymal cells of livers of the opossum, rat, ground squirrel and flying squirrel. Staining of dog liver was moderate and centrilobular. Prosimians were strongly positive: The centrilobular localization was found in the tree shrew and galago; slow lorises and some pottos showed strong reactivity in centrilobular cells and some peripheral cells as well. These prosimians seem to be able to synthesize l-ascorbate as many lower mammals are. On the contrary, true simians (i.e. the squirrel monkey, spider monkey, rhesus monkey and chimpanzee) were negative as guinea pigs were, suggesting their probable inability for l-ascorbate synthesis.

Enzyme-histochemical studies on the hypothalamus with special reference to the supraoptic and paraventricular nuclei of squirrel monkey (Saimiri sciureus)

SummaryDetailed histochemical studies have been made on the distribution of various enzymes such as phosphatases, cholinesterases, glycolytic enzymes and respiratory enzymes in various components of the hypothalamus with special reference to the supraoptic and paraventricular nuclei of the Squirrel Monkey. Cytological studies have also been made by the McManus, Einarson, Gomori and Bargmann methods.A few neurons of these nuclei showed scanty Gomori-positive material in the cytoplasm for the Gomori and Bargmann methods. Nissl granules were located in the peripheral cytoplasm of most neurons. No glycogen granules were observed in these neurons. For these reasons, the Squirrel Monkey, like the rat, may not be a suitable species for the study of neurosecretory phenomena.The axons of these neurons were negative for the specific cholinesterase test, though the perikaryon and some parts of the processes gave a moderately positive reaction. These neurons may be non-cholinergic and the cholinergic fibers from an unknown nucleus may end in synapses on their cell bodies. Blood vessels and glial cells in the neurosecretory nuclei showed non-specific cholinesterase activity. This enzyme may hydrolyze the acetylcholine which has escaped splitting by specific cholinesterase. Alkaline phosphatase and acid phosphatase in these neurons may be involved in the metabolism concerned with the production of neurosecretory material. The neurons may be physicochemical receptors and may get enough energy and raw material to synthesize the neurosecretory material from the rich blood supply. Neurons of the supraoptic and paraventricular nuclei as well as other hypothalamic neurons, like neurons of other regions of the brain, are well equipped with the enzymes of the glycolytic pathways and the tricarboxylic acid cycle. Since the glial cells of these nuclei have amylophosphorylase activity and glycolytic pathways, they may work as energy donators to the neurons of the neurosecretory nuclei.

Enzyme histochemistry of the choroid plexus in rat and squirrel monkey

SummaryThe reactions given for various oxidative and hydrolytic enzymes by the choroid plexus of the squirrel monkey and the rat brain have been studied in detail. The lining cells show strong activity for citric acid cycle and glycolytic pathways enzymes. The stroma shows strong activity for adenosine triphosphatase, alkaline phosphatase, adenosine monophosphatase and glucose-6-phosphatase. The peripheral part or luminal borders of the cytoplasm of the choroidal cells show strong activity for alkaline phosphatase, adenosine monophosphatase and adenosine triphosphatase, and a well developed thiamine pyrophosphatase positive Golgi complex, indicating their participation in the formation and transport of secretory material. The nucleoli of the lining cells give a positive reaction for glucose-6-phosphatase and adenosine triphosphatase. Acid phosphatase like the thiamine pyrophosphatase positive Golgi material is found all over the cytoplasm. The functional significance of these findings is briefly discussed.

Histological and histochemical studies on the rhesus monkey (Macaca mulatta) olfactory mucosa

SummaryDetailed histochemical studies on the localization of various oxidative and dephosphorylating enzymes and esterases have been made on the olfactory mucosa of the rhesus monkey. The upper part of dendritic process and terminal rods of receptor cells and the upper part of supporting cells show high oxidative enzyme activity. The soma and infranuclear parts of receptor and supporting cells have much lower oxidative enzyme activity. The basal cells and perineural epithelial cells have high hydrolytic enzyme activity, though they show low oxidative enzyme activity. Alkaline phosphatase is localized in the olfactory axons, basal cells and perineural epithelial cells. The receptor and supporting cells contain much less adenosine triphosphatase activity than the basal cells and perineural epithelial cells. The axons of receptor cells pass between the basal cells and come out from the basal cell layer forming the olfactory nerve fasciculi, most of which are surrounded completely by flat squamous cells starting from the base of the basal cell layer. The basal cells are histochemically and cytologically related to the perineural epithelial cells covering the olfactory nerve fasciculi. Basal cells probably cannot give rise to supporting cells and are not young forms of supporting cells.The degenerating receptor cells as well as the olfactory nerve fasciculi which are not completely covered by the flat squamous cells may make the locus minoris resistentiae in the olfactory mucosa. The olfactory axons are rich in most of enzymes we have tested. They seem to be metabolically very active and both cholinergic and adrenergic in nature. The mucosal secretion covering the olfactory epithelium contains oxidative and some hydrolytic enzymes. Bowmans glands show high activity for most enzymes except cholinesterases.

Histochemical studies on the distribution of some enzymes of the glycolytic pathways in the olfactory bulb of the squirrel monkey (Saimiri sciureus).

SummaryDetailed histochemical studies on the distribution of glycolytic enzymes have been made in the olfactory bulb of the Squirrel Monkey. The olfactory glomeruli, mitral cells, tufted cells, glial cells and nerve fibers are well equipped with the enzymes of the glycolytic pathways. Granule cells do not have the ability to synthesize or breakdown glycogen, but they have the Embden-Meyerhof-Parnas pathway and the Warburg-Dickens pathway. The synapses of the olfactory glomeruli may have the ability to break-down glycogen for an energy source. Small glial cells found in the olfactory glomeruli may be a special type of oligodendrocyte. Glial cells found abundantly in and around the olfactory glomeruli may be energy donators to the synapses of the olfactory glomeruli. It is suggested that oligodendrocytes and astrocytes of the olfactory bulb may have different branching enzymes.

Enzyme histochemistry of the mesenteric and dorsal root ganglion cells of cat and squirrel monkey

SummaryA detailed histochemical study has been made on the mesenteric ganglia of the cat, and dorsal root ganglia of the squirrel monkey by the use of appropriate histochemical techniques accompanied by appropriate controls for phosphatases, esterases, and oxidative enzymes. The different neurons of a particular ganglion show varied amounts of enzyme activity at a particular time depending upon the functional state of the neurons. SDH, CYO and LDH reaction is prominent in the cytoplasm of the neurons, gliocytes and satellite cells, whereas the MAO preparations generally show a weak reaction. The AK is prominent in the neuropil, cell membranes and peripheral part of cytoplasm, whereas ATPase activity has been observed in blood vessels as well. In AC preparations the area of lipofuscin concentration shows more intense reaction than the rest of the cytoplasm. The activity of AChE and BChE varies from mild, to moderate to strong. The TPPase preparations show morphologically different types and amounts of TPPase positive Golgi material even in the adjoining cells. The relationship between the TPPase Golgi material and various oxidative and dephosphorylating enzymes has been briefly discussed.

Enzyme-histochemical studies on the muscle spindle

SummaryDetailed studies have been made on the distribution of several enzymes in the muscle spindles of the hand and foot interosseous muscles and M. longissimus dorsi of the rhesus monkey as well as in those of the hand interosseous muscles of the squirrel monkey. The intrafusal muscle fibers (IMF) of the rhesus monkey can be classified into two types by the reaction intensity at the polar regions for adenosine triphosphatases and by the enzymes concerning the carbohydrate metabolism except glucose-6-phosphate dehydrogenase, while the extrafusal muscle fibers (EMF) show three types of reactions for the enzymes of the Embden-Meyerhof pathway and the tricarboxylic acid (TCA) cycle. The IMF and EMF of the squirrel monkey are more variable than those of the rhesus monkey for the glycogen breakdown enzyme. It is possible that the small IMF are more capable of energy production through the TCA cycle than the large IMF and the EMF in both species. The positive cholinesterases reactions are found around the polar regions of the IMF, while only the rim of the equator of the IMF shows monoamine oxidase activity. The pericapsular epithelial cells of the muscle spindle seem to be metabolically similar to the perineural epithelial cells.

Histological and histochemical studies on the subfornical organ of the squirrel monkey.

SummaryDetailed studies have been made on the distribution of several enzymes in the subfornical organ (SFO) of the squirrel monkey. In this species, the nerve cells of the SFO show reactions of varying intensity for enzymes of the glycolytic and aerobic pathways. The nerve cells, glial cells and ependymal cells of the SFO and the choroid plexus are equipped with enzymes of the Embden-Meyerhof (EM) pathway, pentose cycle and tricarboxylic acid (TCA) cycle. Many nerve cells and oligodendroglia in the body of this organ are rich in enzymes of the TCA cycle and the pentose cycle and thus presumably have the capacity of producing adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide phosphate (NADPH2) [reduced triphosphopyridine nucleotide (TPNH)]. In the neurons, ATP is probably used as energy for synaptic transmission, active transport, secretion and various other metabolic processes, whereas NADPH2 is used for synthetic processes such as the production of fatty acids and some amino acid conversion (e.g., conversion of phenylalanine into tyrosine). The SFO and its stalks contain both cholinergic and adrenergic neurons and fibers. The outermost layer of the perivascular sheath gives a positive reaction for enzymes of the gylcolytic pathways (EM pathway, pentose cycle and TCA cycle), whereas the inner layer of this sheath shows negligible activity for these enzymes. On the other hand, the whole sheath (inner and outer layers) exhibits strong staining for Mg++-activated adenosine triphosphatase (ATPase), and moderate staining for Ca++-activated ATPase. This sheath, rich in ATPase, may carry on active transport and such related functions. Since the outermost layer contains various enzymes of the glycolytic pathways, it is possible that the ATP required for these functions is produced in this layer.

CORTICAL AREAS and RELATED FIBERS

In this study, the following cortical areas have been described: pre-central and postcentral gyri, visual cortex, hippocampus, amygdaloid complex, tuberculum olfactorium, claustrum, and external and extreme capsule and capsula interna. A general discussion of the histochemistry of these areas follows the cytoarchitechtonic and histochemical observations.