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

The adaptation to repeated, alternate normobaric hypoxic and normoxic exposures (12 h/day, for 5 days) and to pharmacological treatment was evaluated by studying the specific activities of some enzymes related to cerebral energy metabolism. Measurements were carried out on (a) the homogenate in toto, (b) the purified mitochondrial fraction, and (c) the crude synaptosomal fraction in different areas of rat brain--cerebral cortex, hippocampus, corpus striatum, hypothalamus, cerebellum, and medulla oblongata. The adaptation to intermittent normobaric hypoxic-normoxic exposures was characterized by significant modifications of some enzyme activities in synaptosomes (decrease of cytochrome oxidase activity in the hippocampus, corpus striatum, and cerebellum; decrease of malate dehydrogenase activity in the cerebellum) and in the purified mitochondrial fraction (increase of succinate dehydrogenase activity in the corpus striatum). Daily treatment with three doses of naftidrofuryl (10, 15, and 22.5 mg/kg i.m.) modified some enzyme activities affected or unaffected by intermittent hypoxia and, particularly, decreased acetylcholinesterase activity.
J Cereb Blood Flow Metab 1984 Dec
PMID:Effect of prolonged and intermittent hypoxia on some cerebral enzymatic activities related to energy transduction. 650 47

The maximal rate of some cerebral enzymatic activities related to energy transduction (hexokinase; phosphofructokinase; lactate dehydrogenase; citrate synthase; malate dehydrogenase; total NADH-cytochrome c reductase; cytochrome oxidase), amino acid metabolism (glutamate decarboxylase; glutamate dehydrogenase) and cholinergic metabolism (acetylcholine esterase) were tested in the cerebral cortex and in sub-cortical area of rats. The evaluations were performed both in the homogenate in toto and in the crude mitochondrial fraction, before and after a postdecapitative normothermic ischemia of 5, 10, 20, and 40 min duration. The results are discussed also with respect to the pharmacological pretreatment with two biological substances which may modulate amino acid (L-alanine) and phospholipid metabolism (CDP-choline). The analysis of the present data suggests the occurrence in brain tissue of a variety of interrelated factors implicated in the ischemia-induced changes of the maximal rate of the enzymatic activities related to the energy transduction. These include: (a) rearrangement of the enzymatic activities because of the changed metabolic and chemico-physical condition; (b) decrease in the activity of enzymes related to the electron transfer chain and glycolysis; (c) changes in enzymes related to mitochondrial membranes. The effects of in vivo administration of alanine or CDP-choline, even if significant, are not consistent throughout the time period studied.
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PMID:Changes induced by ischemia on some cerebral enzymatic activities related to energy transduction and amino acid metabolism. 685 30

Optical imaging of intrinsic signals was performed in the barrel cortex of the rat during whisker deflections of varying frequencies (1 to 20 Hz) and durations (0.1 to 5 s). A dose-response relationship was shown between these stimuli and the characteristics of the optically recorded intrinsic signal response. At constant frequencies, longer stimulus durations increased response magnitude, as defined by mean pixel value in statistically determined regions of interest. At constant durations, higher stimulus frequencies increased response magnitude. Response magnitude was also increased by greater numbers of deflections. When stimulus number was constant, there were no differences in response magnitude, regardless of stimulus frequency and duration. Spatial extent of responses, as defined by number of pixels in regions of interest, did not differ between stimulus frequencies, durations, or numbers. Comparison of the time to reach peak intrinsic signal response after stimulus onset ("time-to-peak") suggested that higher frequencies were associated with faster time-to-peak. Registration of intrinsic signal responses with cytochrome oxidase-stained whisker barrels demonstrated that responses were located over the barrel corresponding to the stimulated whisker. In summary, we have shown that the absolute number of stimuli delivered to the system is, at least for short stimulus periods (< or = 5 s), a determining factor for the magnitude of these responses, whereas stimulus frequency appears to influence time-to-peak response.
J Cereb Blood Flow Metab 1995 Nov
PMID:Stimulus parameters influence characteristics of optical intrinsic signal responses in somatosensory cortex. 759 44

Protein phosphorylation and dephosphorylation play an important role in neuronal signal transduction. In this study the distribution of calcineurin, a calcium/calmodulin-dependent protein phosphatase, was investigated in the striate cortex of two Old World monkeys, Macaca fascicularis and Papio anubis, using a well-characterized, affinity-purified polyclonal antibody to calcineurin. In order to relate the calcineurin distributions to established cytochemical markers, adjacent sections were processed for the visualization of cytochrome oxidase. The staining patterns obtained from the two species were remarkably similar. The results indicate that (1) monkey striate cortex exhibits strong calcineurin-like immunoreactivity that is present both in the neuropil and in neurons, most of which have characteristics of pyramidal cells; (2) the distribution of calcineurin is laminar specific; and (3) it is complementary to that of cytochrome oxidase activity with respect to both its laminar and its tangential pattern. In sections perpendicular to the cortical lamination calcineurin immunoreactivity is high in layers II and III, reduced in layer IVA, nearly as dense as in supragranular layers in layer IVB, minimal in layer IVC, and again enhanced, but not as much as in supragranular layers, in layers V and VI. In addition to these lamina-specific variations, the density of calcineurin-like immunoreactivity exhibits a periodic modulation along trajectories parallel to the pial surface that is most marked in layer III but also discernable in infragranular layers. Accordingly, in tangential sections through supragranular layers the calcineurin distribution is mosaic-like with patches of high density corresponding to cytochrome-poor regions (interblob regions) and zones of low density corresponding to areas of high cytochrome oxidase activity (blobs).
Cereb Cortex
PMID:Laminar and columnar organization of immunoreactivity for calcineurin, a calcium- and calmodulin-regulated protein phosphatase, in monkey striate cortex. 770 89

We stained human visual cortex for myelin, cytochrome oxidase, and the monoclonal antibody CAT-301 in an attempt to demonstrate and map MT (V5) and other visual cortical areas in humans. Both flattened and unflattened cortical tissue was examined. A likely candidate for area MT (V5), which we refer to as MT, was demonstrated using all three stains. Myelin and CAT-301 labels for MT were demonstrated to be coincident by comparing results from the two stains in adjacent sections. In all three stains, MT was an oval area approximately 1.2 x 2.0 cm, located 5-6 cm anterior and dorsal to the foveal V1-V2 border. The position and size of MT as defined by the present anatomy are consistent with MT (V5) as defined by functional measures in humans. In addition, flattened cortical tissue stained for cytochrome oxidase revealed a distinctive staining topography in several cortical areas, including areas V1, V2, MT, PX, and VX. Similar studies in flattened cortex of macaque and green monkeys demonstrated distinctive dark cytochrome oxidase staining in MT, PX, MTc, and V3.
Cereb Cortex
PMID:Anatomical evidence for MT and additional cortical visual areas in humans. 771 29

Area V2, the main target of primary visual cortex projections, is characterized by a striking functional and connectional compartmentalization. Many aspects of this organization are correlated to three sets of stripes (thick, thin, and pale) revealed by cytochrome oxidase (CO) staining. Several questions related to the physiological properties of these compartments, their intrinsic connections, and points of similarity with area V1 modules are still unresolved. We have addressed some of these questions by combining the techniques of optical imaging of intrinsic signals, tract tracing, and CO histochemistry in the same patches of areas V1 and V2 of the squirrel monkey. The following observations were made. Orientation domains: in area V1 these are organized in narrow bands, while in area V2 they form patches. In area V2, domain width and distance between domains are approximately double that found in area V1. Orientation and CO stripe organization: orientation tuning was organized so that highly selective regions were centered on thick CO stripes while regions of broad orientation selectivity were centered on thin CO stripes. However, the orientation domains appeared to ignore borders between thick and pale stripes. Intrinsic connections: injections of the sensitive tracer biocytin into area V2 labeled a dense network of horizontally projecting fibers that were organized in columnar patches. Patches were small (mean width, 211 microns; mean length, 342 microns) and the labeling pattern extended over 4-5 mm. Axonal patches and CO stripes: Axonal patches found were in all three stripe compartments. However, injections that straddled the borders of thick/pale stripe compartments produced axonal projections that tended to cluster around border regions. Axonal patches and orientation domains: V2 injections produced labeling in V1 that appeared to be organized in narrow bands, reminiscent of orientation domain distribution in V1. Within area V2, axonal patches targeted a wide range of orientation domains, but appeared to avoid domains having orthogonal orientation preference to that found at the injection site. To conclude, our results show, on the one hand, a measure of functional specificity for the CO stripes and the intrinsic connections. On the other hand, they indicate additional substructures within area V2, whose precise relationship to the known compartmental organization remains to be clarified.
Cereb Cortex
PMID:Relationship between orientation domains, cytochrome oxidase stripes, and intrinsic horizontal connections in squirrel monkey area V2. 803 66

The organization of peristriate cortex was studied in nine flying foxes (genus Pteropus). Based on receptive field mapping and architectonic data, we report on the organization of the second visual area (V2). V2 forms a continuous belt 2-4 mm wide bordering V1 anteriorly. In each hemisphere, V2 contains a precisely organized representation of the entire contralateral visual field. The vertical meridian of the visual field (VM), and a short strip of the ipsilateral hemifield are represented at the posterior border of V2, with V1. The area centralis is represented approximately at the center of the posterior border of V2. At each mediolateral level, progressively more peripheral portions of the visual field are represented as V2 is crossed from posterior to anterior. The representation of the upper quadrant is continuous, and confined to the lateral half of V2. In contrast, the representation of the lower quadrant is split along a line running from the temporal edge of the field of vision to the optic disk. As a result of this arrangement, the portions of the lower quadrant close to the VM are represented medially, and those away from the VM laterally in V2. The entire representation of the horizontal meridian is located in lateral V2, and is not split between medial and lateral V2 as in primates. The linear cortical magnification factor (CMF) decays by a factor of 3-5 from the central to the peripheral representation. The CMF is anisotropic, and equal distances in the visual field are magnified twice as much parallel to the V1/V2 border than perpendicular to this border. Moreover, points in the lower quadrant are magnified relative to symmetrical points in the upper quadrant. V2 is histologically distinct from all surrounding areas in both cytochrome oxidase- and Nissl-stained sections. These results suggest that V2 is an homologous area common to all archontans, and imply that much of the variability reported among mammals may be due to technical factors, rather than true species differences.
Cereb Cortex
PMID:Organization of the second visual area in the megachiropteran bat Pteropus. 818 Apr 91

A microscopic reflectance spectrophotometer was constructed to obtain the spectra of single pial vessels and of a region containing only capillaries (capillary region). The difference in the oxygen saturation (SO2) of hemoglobin between the regional arteriole and venule [R(A - V)] and that between the regional arteriole or capillaries [R(A - C)] were calculated. The reduction of cytochrome aa3 was also estimated in the capillary region. This method was applied to the brain surface of spontaneously breathing rats subjected to hypoxic and anemic hypoxia. On decreasing the inhaled O2 from 100 to 15%, elevation of R(A - V) and R(A - C) with slight arteriolar dilatation (though statistically not significant) was observed. Below 10% O2 (especially at 4 and 3% O2), the R(A - V) and R(A - C) decreased in spite of significant arteriolar dilatation with progressive reduction of cytochrome aa3, indicating suppression of oxygen transport to mitochondria. In the case of hemodilution down to 37% hematocrit (Ht), elevation of R(A - V) and R(A - C) occurred with a slight tendency toward arteriolar dilatation. Below 32% Ht, the R(A - V) decreased but the R(A - C) remained steady, while reduction of cytochrome aa3 progressed. Altogether, the SO2 in the capillary region decreased and the reduction of cytochrome aa3 progressed with the decline of arteriolar O2 supply in both hypoxic and anemic hypoxia.
J Cereb Blood Flow Metab 1994 Jan
PMID:Intravital microreflectometry of individual pial vessels and capillary region of rat. 826 61

Monocular deprivation produces an imbalance in visual drive from the two eyes, which in adult macaque V1 leads to marked changes in the neurochemistry of GABA interneurons. Such changes were further examined by studying immunoreactivity for calbindin, calretinin, and parvalbumin, three calcium-binding proteins that mark distinct subpopulations of GABA neurons, in macaques that had been monocularly deprived by intravitreal injection of tetrodotoxin. Deprivation for 5 d or longer produced a reversal in the normal pattern of calbindin immunostaining in layer III, from one in which intense neuronal immunostaining surrounded the cytochrome oxidase-rich puffs to one in which it occupied the puffs. Over the same period, calbindin immunostaining in other layers was reduced across the entire width of deprived-eye columns or extended into flanking regions of normal-eye columns. In contrast, reduction in parvalbumin immunostaining occurred only in deprived-eye columns and included only terminals with short periods of deprivation (up to 17 d) but both terminals and somata with longer periods. No change in calretinin immunoreactivity was observed. These findings demonstrate that GABA neurons of macaque V1 vary in their response to monocular deprivation according to their neurochemistry and position, suggesting that the weight of inputs from the two eyes and the intrinsic characteristics of each GABA population determine how a neuron responds to a change in visual input.
Cereb Cortex
PMID:Regulation of calcium-binding protein immunoreactivity in GABA neurons of macaque primary visual cortex. 867 Jun 56

To help understand the role of long-range, clustered lateral connections in the superficial layers of macaque striate cortex (area V1), we have examined the relationship of the patterns of intrinsic connections to cytochrome oxidase (CO) blobs, interblobs, and ocular dominance (OD) bands, using biocytin based neuroanatomical tracing, CO histochemistry, and optical imaging. Microinjections of biocytin in layer 3 resulted in an asymmetric field (average anisotropy of 1.8; maximum spread--3.7 mm) of labeled axon terminal clusters in layers 1-3, with the longer axis of the label spread oriented orthogonal to the rows of blobs and imaged OD stripes, parallel to the V1/V2 border. These labeled terminal patches (n = 186) from either blob or interblob injections (n = 20) revealed a 71% (132 out of 186) commitment of patches to the same compartment as the injection site; 11% (20 out of 186) to the opposite compartment, and 18% (34 out of 186) to borders of blob-interblob compartments, indicating that the connectivity pattern is not strictly blob to blob, or interblob to interblob (p < 0.005; chi(2)). In injections placed within single OD domains (n = 11), 54% of the resulting labeled terminal patches (43 out of 79) fell into the same OD territories as the injection sites, 28% (22 out of 79) into the opposite OD regions, and 18% (14 out of 79) on borders, showing some connectional bias toward same-eye compartments (p < 0.02; ANOVA). Individual injection cases, however, varied in the degree (50-100% for CO patterns, 22-100% for OD patterns) to which they showed same-compartment connectivity. These results reveal that while connectivity between similar compartments predominates (e.g., blob to blob, right eye column to right eye column), interactions do occur between functionally different regions.
Cereb Cortex
PMID:Relation between patterns of intrinsic lateral connectivity, ocular dominance, and cytochrome oxidase-reactive regions in macaque monkey striate cortex. 867 Jun 58


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