Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.9.3.1 (cytochrome oxidase)
 8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neuronal cell bodies and synaptic terminals positive for glutamic acid decarboxylase, the enzyme responsible for synthesizing gamma-amino butyric acid, have been located by immunocytochemical staining in all layers of the macaque monkey cortex. In layers II and III the staining pattern of periodic dots is identical with that seen in sections stained for cytochrome oxidase. The rows of dots run parallel with the ocular dominance columns, suggesting that the labelled neurones are preferentially related to each eye.
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PMID:Immunocytochemical localization of glutamic acid decarboxylase in monkey striate cortex. 626 4

We examined the pattern of cytochrome oxidase (CO), Nissl staining, and gamma-amino butyric acid (GABA) immunoreactivity in the ventroposterior lateral nucleus (VPL) of the thalamus in monkeys that received no, total, or subtotal, ablation of the hand representations in postcentral somatosensory cortex. In unoperated animals, the region of VPL representing the hand was characterized by relatively dense and homogeneous CO staining throughout the rostral-caudal extent of VPL. Counts of neurons in the VPL hand representation from adjacent thalamic sections processed for Nissl and GABA immunostaining indicated that there were approximately 261.4 neurons/mm2 of which 78.4/mm2 stained positive for GABA. GABA(+) puncta-like terminals were readily apparent throughout the VPL. By contrast, animals that received total removals of the postcentral hand representations showed a dramatic reduction in CO staining in the VPL, which was confined to the expected location of the thalamic hand representation. Counts of neurons in the affected region from adjacent sections that underwent Nissl staining and GABA immunostaining also revealed a dramatic reduction of Nissl-stained neurons, with a smaller reduction in the number of neurons staining positive for GABA. Specifically, large to medium-sized (> 180 microns 2) GABA(-) neurons were virtually eliminated in the affected portion of the VPL, and the numbers of GABA(+) neurons were significantly reduced. The remaining population of GABA(+) neurons was typically shrunken, and no GABA(+) puncta-like terminals were observed in the affected region. The results obtained after subtotal ablation of the postcentral hand representations (only one postcentral area spared, 3b or 3a) differed from those obtained when total removals were made. Instead of virtually complete degeneration of medium-sized to large neurons throughout the hand representation in VPL, as was the case with total removals, after partial removals, we found alternating regions in the VPL hand representation that appeared qualitatively normal, or dramatically degenerated. Thalamic sections stained with CO revealed light, moderate, and darkly stained patches of label within the hand representation in VP, depending on the type of cortical ablation. The most dramatic reduction of Nissl-stained neurons coincided precisely with the lightest staining CO patches. Interestingly, the only statistically significant reduction in the number of GABA(+) neurons occurred in the light CO patches. In the thalamic regions coincident with the dark and moderately stained CO patches, the number of medium-sized and large neurons decreased, but the number of GABA(+) neurons was comparable to normal. Optical density measurements of the dark patches also indicated a statistically significant difference from normal CO staining in this region.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Patterns of thalamocortical degeneration after ablation of somatosensory cortex in monkeys. 854 46

A patient with Parkinson's disease received bilateral fetal human nigral implants from six donors aged 6.5 to 9 weeks post-conception. Eighteen months following a post-operative clinical course characterized by marked improvement in clinical function, this patient died from events unrelated to the grafting procedure. Post-mortem histological analyses revealed the presence of viable grafts in all 12 implant sites, each containing a heterogeneous population of neurons and glia. Approximately 210,146 implanted tyrosine hydroxylase-immunoreactive (TH-ir) neurons were found. A greater number of TH-ir grafted neurons were observed in the right (128,162) than the left (81,905) putamen. Grafted TH-ir neurons were organized in an organotypic fashion. These cells provided extensive TH-ir and dopamine transporter-ir innervation to the host striatum which occurred in a patch-matrix fashion. Quantitative evaluations revealed that fetal nigral grafts reinnervated 53% and 28% of the post-commissural putamen on the right and left side, respectively. Grafts on the left side innervated a lesser area of the striatum, but optical density measurements were similar on both sides. There was no evidence that the implants induced sprouting of host TH-ir systems. Electron microscopic analyses revealed axo-dendritic and occasional axo-axonic synapses between graft and host. In contrast, axo-somatic synapses were not observed. In situ hybridization for TH mRNA revealed intensely hybridized grafted neurons which far exceeded TH mRNA expression within residual host nigral cells. In addition, gamma-amino butyric acid (GABA)-ergic neurons were observed within the graft that formed a dense local neuropil which was confined to the implant site. Serotonergic neurons were not observed within the graft. Cytochrome oxidase activity was increased bilaterally within the grafted post-commissural putamen, suggesting increased metabolic activity. In this regard, a doubling of cytochrome oxidase activity was observed within the grafted post-commissural putamen bilaterally relative to the non-grafted anterior putamen. The grafts were hypovascular relative to the surrounding striatum and host substantia nigra. Blood vessels within the graft stained intensely for GLUT-1, suggesting that this marker of blood--brain barrier function is present within human nigral allografts. Taken together, these data indicate that fetal nigral neurons can survive transplantation, functionally reinnervate the host putamen, establish synaptic contacts with host neurons, and sustain many of the morphological and functional characteristics of normal nigral neurons following grafting into a patient with PD.
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PMID:Functional fetal nigral grafts in a patient with Parkinson's disease: chemoanatomic, ultrastructural, and metabolic studies. 880 31

The primary visual cortex (V1) of primates is unique in that it is both the recipient of visual signals, arriving via parallel pathways (magnocellular [M], parvocellular [P], and koniocellular [K]) from the thalamus, and the source of several output streams to higher order visual areas. Within this scheme, output compartments of V1, such as the cytochrome oxidase (CO) rich blobs in cortical layer III, synthesize new output pathways appropriate for the next steps in visual analysis. Our chief aim in this study was to examine and compare the synaptic arrangements and neurochemistry of elements involving direct lateral geniculate nucleus (LGN) input from the K pathway with those involving indirect LGN input from the M and P pathways arriving from cortical layer IV. Geniculocortical K axons were labeled via iontophoretic injections of wheat germ agglutinin-horseradish peroxidase into the LGN and intracortical layer IV axons (indirect P and M pathways to the CO-blobs) were labeled by iontophoretic injections of Phaseolus vulgaris leucoagglutinin into layer IV. The neurochemical content of both pre- and postsynaptic profiles was identified by postembedding immunocytochemistry for gamma-amino butyric acid (GABA) and glutamate. Sizes of pre- and postsynaptic elements were quantified by using an image analysis system, BioQuant IV. Our chief finding is that K LGN axons and layer IV axons (indirect input from M and P pathways) exhibit different synaptic relationships to CO blob cells. Specifically, our results show that within the CO blobs: 1) all K cell axons contain glutamate, and the vast majority of layer IV axons contain glutamate with only 5% containing GABA; 2) K axons terminate mainly on dendritic spines of glutamatergic cells, while layer IV axons terminate mainly on dendritic shafts of glutamatergic cells; 3) K axons have larger boutons and contact larger postsynaptic dendrites, which suggests that they synapse closer to the cell body within the CO blobs than do layer IV axons. Taken together, these results suggest that each input pathway to the CO blobs uses a different strategy to contribute to the processing of visual information within these compartments.
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PMID:Synaptic and neurochemical characterization of parallel pathways to the cytochrome oxidase blobs of primate visual cortex. 948 23