Dinámica de la córticoangiogénesis en el sistema nervioso central / Dinamics of the cortico-angiogenesis in the central nervous system

This study analyzes the temporal-spatial correlation between angio-and corticogenesis in the developing chick optic tectum (OT) by means of NADPH-diaphorase and immunolabeling methods. Qualitative and quantitative parameters were used to analyze a new vessels formation and growth of preexisting ones as a function of time and space...

Immuno and cytochemical localization of Trypanosoma cruzi nitric oxide synthase

The localization and subcellular distribution of Trypanosoma cruzi nitric oxide synthase was investigated in epimastigote cells by immunocytochemistry at electron and light microscope level, using a polyclonal antibody to neuronal nitric oxide synthase, and also, at light microscope level, by the nicotinamide adenine dinucleotide phosphate-diaphorase histochemical reaction. The immunoreactivity was ultrastructurally localized by electron microscopy in the inner surface of cell membranes and in free cytosolic clusters in the body, flagellum and apical extreme. Light microscopy showed that immunoprecipitates, specific for the Trypanosoma cruzi nitric oxide synthase, co-localized with the formazan precipitates generated by the diaphorase reaction in the same areas identified by electron microscopy. These results, taken together with previous finding from our laboratory could help to explain the involvement of the nitric oxide transduction pathway in T. cruzi epimastigote motility.

Serotonergic ependymal fibres in rat and monkey: light and electron microscopic immunocytochemical study

The distribution of serotonin (5HT) immunoreactive fibres in the ependymal epithelium of aqueductus cerebri in adult rat and monkey was studied by means of immunocytochemical methods using specific antibodies against 5HT. Light microscopic examination of immunostained coronal sections of mesencephalon showed, in tryptophan and pargylin pretreated animals, abundant serotonergic fibres distributed along the ependymal cells of the aqueduct, forming supraependymal and subependymal plexi. Serotonin fibres lying either supraependymally or ending freely in the aqueduct lumen contributed to the formation of a rich 5HT containing network on the ependymal surface. Electron microscope images showed dense 5HT-immunoreactive (5HT-IR) profiles with ultrastructural characteristics of axon terminals ending on the ependymal cells. Dense diaminobenzidine (DAB) deposits were found in the axoplasm, on outer mitochondrial surface and in vesicles. No synaptic contacts were observed between 5HT-IR terminals and ependymal cells. Unstained microvilli and cilia were also observed in the aqueduct lumen. Serotonin immunoreactivity disappeared from ependymal fibres in animals treated with parachlorophenylalanine, an inhibitor of 5HT synthesis. 5HT containing fibres described in this paper may be the source of 5HT and its metabolite 5-hydroxyindoleacetic acid (5HIAA) found in cerebrospinal fluid (CSF) and of clinical relevance in some psychiatric conditions such as depression, suicidal attempts, etc

Distribution of GABA in the golden hamster retina: An immunocytochemical study

Distribution of the inhibitory neurotransmitter GABA was studied in the golden hamster retina using immunocytochemistry at cellular and subcellular levels. GABA-immunoreactivity was observed in somata of amacrine, displaced amacrine and horizontal cells. GABA immunoreactive fibers were abundant in the inner plexiform layer. Ultrastructural analysis exhibited dense GABA-immunoreactive deposits in amacrine cell somata, processes and terminals. Immunolabelling was also observed in the cytoplasm of horizontal or interplexiform cells and displaced amacrine cells. In every case DAB deposits were observed in the cytosolic compartment, attached to the inner surface of cell membranes and to outer mitochondrial membranes. Immunolabeled terminals predominated in the inner plexiform layer and immunoprecipitates were also observed attached to the outer face of vesicle membranes as well as completely filling synaptic vesicles. Both clear and dense core vesicles were observed. The present results are similar to those obtained in other mammalian species showing GABA immunoreactivity in amacrine, displaced amacrine and horizontal cells

Ultrastructural study of cell injury induced by coxsackievirus B3 in pancreatic and cardiac tissues

Con fines de una mejor caracterización de la injuria celular provocada por el coxsackievirus B3 en páncreas y corazón, ratones Balb/C ya destetados fueron intraperitonealmente inoculados con una variante miocardítica de ese serotipo viral. A nivel ultraestructural, las células pancráticas acinosas mostraron evidente distorsión, evidenciada por acentuada pérdida de organelas y de gránulos de zimógeno, así como apreciable dilatación del retículo endoplásmico granuloso. En cuanto a las células cardíacas, las alteraciones citoesqueléticas fueron severas, llegando a incluir colapso de miofibrilas con disminuición de su número e irregularidad en su disposición. Además, los cardiomiocitos exhibieron cromatina de distribución irregular y mitocondrias de tamaño agranado. A la vez de los focos necróticos tendían a desaparecer, el número de fibroblastos aumentaba en forma coincidente a la progresiva cicatrización de la lesión. Los cambios ultraestructurales observados en páncreas y corazón fueron concomitantes en consecuencia que el daño celular era atribuíble a la acción directa del virus

Immunocytochemical localization of sorotonin in the pineal gland

Se estudió la localización de serotonina (5HT) en la glándula pineal de ratas en condiciones de luz diurna por medio de microscopía óptica y electrónica. Se usó un anticuerpo policlonal para 5 HT y el método inmunocitoquímico de peroxidasa antiperoxidas (PAP). La glándula mostró fibras varicosas inmunomarcadas distribuidas por toda su extensión. Las observaciones ultraestructurales revelaron la presencia de depósitos electrodensos de diaminobencidina (DAB) en terminales localizados principalmente en los espacios perivasculares