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K Sugioka

Publications and source records attributed to K Sugioka.

At least 19 recordsLinked to original sources
PubMed1997

Projections from the subdivisions of the fastigial nucleus to the vestibular complex and the prepositus hypoglossal nucleus in the albino rat: an anterograde tracing study using biocytin.

Differential projections from the subdivisions of the fastigial nucleus to the vestibular complex and the prepositus hypoglossal nucleus were investigated by an anterograde tracing method using biocytin in the albino rat. The caudomedial subdivision of the nucleus projected ipsilaterally to the dorsal and medial parts of the superior vestibular nucleus (Su Ve), the dorsomedial part of the lateral vestibular nucleus (LVe), and the dorsal parts of the medial (MVe) and spinal (Sp Ve) vestibular nuclei, and projected contralaterally to the ventrolateral corners of the Su Ve and LVe, the ventral part of the MVe, and the lateral part of the Sp Ve. The bilateral prepositus hypoglossal nuclei received sparse projections from the caudomedial subdivision. The middle subdivision of the fastigial nucleus projected ipsilaterally to the dorsal and/or ventral parts of the Su Ve, the dorsomedial pats of the LVe and Sp Ve, and the dorsolateral part of the MVe, and projected contralaterally to the dorsal margin of the Su Ve, the ventrolateral part of the LVe, and the lateral part of the Sp Ve. The dorsolateral protuberance of the fastigial nucleus projected ipsilaterally to the dorsal margin of the Su Ve, the dorsomedial part of the LVe, the dorsal or lateral parts of the Sp Ve, and the lateral part of the MVe, and projected contralaterally to the ventrolateral part of the LVe and the lateral part of the Sp Ve. The subnuclei x, y, and f, interstitial nucleus of the vestibular nerve, and the infracerebellar nucleus received bilateral or ipsilateral fastigiovestibular projections.

Animals↗
PubMed1996

Retrograde fluorescent double-labeling study of bilaterally projecting retinal ganglion cells in albino rats at different stages of development.

Injection of the fluorescent tracers 10% Evans blue (EB) and 4% fluoro-gold (FG) into the right and the left dorsal lateral geniculate nucleus, respectively, of albino rats at different stages of development demonstrated the presence of double-labeled retinal ganglion cells that projected bilaterally into both the dorsal lateral geniculate nuclei (dLGN). Findings confirmed that the distribution of these double-labeled cells was gradually reduced after birth, being confined to the peripheral temporoventral quarter (temporal-ventral crescent) of the retina after postnatal day 15. We estimated the proportion of double-labeled cells to total labeled cells in the same area at different stages of development (0-90 days); values ranged from 35.3% in the neonate to 5.27% in the adult rat which suggests that the majority of double-labeled cells and/or their axons were lost early in development. That a small number of ganglion cells were observed to project bilaterally in the adult rats suggested that these cells conduct the same visual information to both hemispheres throughout the animal's life.

Animals↗
PubMed1996

Demonstration of direct input from the retina to the lateral habenular nucleus in the albino rat.

The projection from the retina to the habenular complex was studied using fluorescent retrograde tracers in the albino rat (Wistar, Japan Clea). Following separate unilateral injections of Fluoro-Gold (FG), Fluoro-Ruby (FR), or 4-acetamido,4- isothiocyanostilbene-2,2'-disulfonic acid (SITS) into the lateral habenular nucleus (LHB), a small population of ganglion cells was labeled sporadically, predominantly those in the nasal retina contralateral to each injection site. Most of them were small cells, ranging from 9 to 16 mu m in diameter, roughly corresponding to the type III ganglion cell in the rat retina. Additionally, all of the structures previously described as regions projecting to the LHB were confirmed. Upon re-examination of previous brain sections of albino rats which had undergone monocular enucleation, degenerating retinal nerve axons and/or their terminals, stained by a modified selective silver impregnation method, were observed in the well-documented end regions of retinal afferents as well as the LHB. The degenerating retino-habenular nerve terminals were distributed sparsely and restricted mainly to the caudal part of the LHB contralateral to the side of ocular enucleation. The present experimental data provide evidence for the existence of a non-image forming retino-habenular pathway in the albino rat. We suggest that, besides serving as a point of convergence for some of the major conduction channels of the limbic and striatal systems, the LHB may play more general integrative roles, including participation in the integration of visual information.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed1996

A case of the bilateral superficial brachial arteries which continued to the radial arteries in the forearms.

During the dissection course of Kobe University School of Medicine, we found the bilateral superficial brachial arteries that continued to the radial arteries in a 90-years-old female cadaver. Each superficial brachial artery is classified Arteria brachialis superficialis lateralis inferior. This artery directly continued to the radial artery in the forearms on each side. Anomalous branching patterns of the (proper) brachial artery in this case belong to the type 7 of Adachi's classification. The incidence and embryological aspects of this anomalous arterial branching are discussed.

Aged↗
PubMed1995

Bifurcated projections of retinal ganglion cells bilaterally innervate the lateral geniculate nuclei in the cat.

Cats were injected with the fluorescent retrograde tracers, Fluoro-Gold (FG) and Evans Blue (EB), into the left and right lateral geniculate nuclei (LGN), respectively. About 4.56% of the ganglion cells in the temporal retina were double-labeled by these dyes. 4.7% of these cells were of the large type, 30.3% were of the medium type, and 65% were classified as cells of the small type. These results indicate that members of all three ganglion cell size classes, mainly those of small type, bilaterally innervate the LGN via axonal bifurcation.

Animals↗
PubMed1995

A study of double-labeled retinal ganglion cells from the superior colliculus in the developing albino rat.

We studied the distribution pattern and percentage of bilaterally projecting, double-labeled retinal ganglion cells in the albino rat by the retrograde fluorescent double labeling. Forty-five albino (Wistar, Japan Clea) rats of either sex and of different stage of development ranging in age from the day of birth (Day 0) to Day 30, were used. With the rats under deep anesthesia, we pressure injected 0.02 microliter of 15% Evans blue (EB) and 0.02 microliter of 4% Fluoro-gold (FG) into the right and left superior colliculi, respectively; for rats older than 5 days, the volume of each tracer was 0.04 microliter. The animals were perfused with formol-saline 48 to 72 h later and the brain and eyeballs were excised and sectioned. Double-labeled cells were found over almost the entire retina, with the concentration in the lower temporal crescent in rats up to day 1; concentration gradually shifted to the ventral half between days 5 and 10. After day 15, double-labeled cells were found only in the ventral-temporal crescent of the retina, which is the pattern in the adult rats. The percentages of retinal ganglion cells that were double-labeled at days 0, 1, 5, 7, 10, 15, 20, 25 and 30 were 60.2, 51.6, 60.5, 57.6, 62.2, 60.7, 55.7, 45.2, and 39.1, respectively. After day 10, the percentage of such cells decreased steadily.

Animals↗
PubMed1995

Bifurcating projections from the retinal ganglion cells to the primary visual targets (SC and LGN) in the cat.

Bifurcating projections of retinal ganglion cells to the primary visual targets were studied in the cat using a retrograde fluorescent double-labeling technique with Fluoro-Gold (FG) and Evans Blue (EB) as the tracers. Following injections of FG and EB into the left and right lateral geniculate nuclei (LGN), or into the left and right superior colliculi (SC), or LGN and SC on the same side, 4.56% of the single-labeled cells with one tracer were simultaneously labeled by the other tracer injected contralaterally in bilateral LGN-injection group; 12.18% of the single-labeled cells were further labeled by the other tracer injected contralaterally in bilateral SC injection-group; and 8.95% of the single-labeled cells in the ipsilateral retina, 10.94% of the single-labeled cells in the contralateral retina by the tracer injected into the LGN were labeled by the other tracer injected into the SC on the same side. All three retinal ganglion cell classes by size demonstrated double-labeled cell bodies. In the bilateral LGN- and bilateral SC-injection groups, the double-labeled cells were mainly of the small type (65% and 82.8%, respectively), while in the group of the injections into the LGN and SC on the same side, double-labeled cells were predominantly of the large type (55.45%). These results indicate that single ganglion cells of the retina send bifurcated projections to the bilateral LGN, bilateral SC, or unilateral LGN and SC, via axonal collaterals. These bifurcated axons can be regarded as an important way by which the information of the single ganglion cells can be conducted to the same primary visual targets on both sides, and two different optic centers on the same side of the brain.

Animals↗
PubMed1995

Afferent projections to the cingulate cortex in albino rats: a study with a retrograde labeling method using fluoro-gold.

We studied the neuronal populations that project their axons to the cingulate cortex in albino rats using the retrograde fluorescent dye of 4% Fluoro-Gold injected into the anterior, middle and posterior portions of the cingulate cortex. The result showed that the following ipsilateral structures are sending fibers to these three portions: the prefrontal cortex, frontoparietal motor cortex, indusium griseum, dorsal endopiriform nucleus, lateral part of medial mammillary nucleus, nuclei of diagonal band of Broca, anterior pretectum, anterior part of caudate-putamen, hippocampal formation, anteroventral, anteromedial, lateroposterior, ventroposterior and dorsomedial thalamic nuclei. The anterior portion of the cingulate cortex receives inputs from the following ipsi- and contralateral structures: the accessory olfactory bulbs, anterior olfactory nuclei, middle and posterior portions of the cingulate cortex. The middle cingulate cortex receives fibers only from the ipsilateral dorsal part of the lateral septal nucleus in addition from the ipsi- and contralateral anterior and posterior portions of the cingulate cortex. While the posterior portion of the cingulate cortex receives separate inputs from the following ipsilateral structures: anterodorsal thalamic nucleus, temporal cortex, entorhinal cortex, areas 17 and 18, as well as from the ipsi- and contralateral anterior and middle portions of the cingulate cortex. The present study shows that the cingulate cortex receives various kinds of inputs from the other parts of the brain which are involved in emotion, memory, vision and motion, and also suggests that there are differences in afferent projections among the anterior, middle and posterior portions of the cingulate cortex.

Afferent Pathways↗
PubMed1994

Cerebral ischemia alters glucose transporter kinetics across rat brain microvascular endothelium. Quantitative analysis by an in situ brain perfusion method.

The purpose of this study was to quantify the changes of blood-brain barrier glucose transporter kinetics following cerebral ischemia using an in situ brain perfusion technique. Sixty-four adult male Sprague-Dawley rats were divided into control and ischemia groups, and a four-vessel occlusion model was used to provide an ischemic insult. To obtain regional capillary permeability area products of glucose and regional perfusion fluid flow rates, the perfusion fluid was dually labeled with 2-deoxy[14C]glucose and [3H]diazepam, and the brain was perfused at a constant rate via the external carotid artery. After sampling tissues from the brain, dual scintillation counting was performed and both regional perfusion fluid flow rates and regional capillary permeability area products were calculated. We determined kinetic parameters, including Vmax, Km and Kd as described in the Michaelis-Menten equation, by the non-linear least squares method. In the ischemia group, a decrease in Vmax and an increase in Km were recognized, which mean decreases in the affinity and the number of functioning glucose transporters. These results suggest that cerebral ischemia downregulates the blood-brain barrier glucose transporters.

Animals↗
PubMed1992

A [14C]2-deoxy-D-glucose study of brain structures related to conditioned emotional response in the rat.

We used [14C]2-deoxy-D-glucose (2-DG) to determine activated brain structures related to conditioned emotional response (CER) in rats. The experimental groups were conditioned with paired conditioned-stimulus (CS; flickering light and clicking sound) and unconditioned-stimulus (US; foot-shock) for either 25 or 50 trials. The control groups were also exposed to the same stimuli but in unpaired or random sequence. Two days after conditioning, rats were intravenously injected with [14C]2-DG and then exposed to the CS alone (CER test) in a shock box. Mean optical densities of 44 brain structures were measured with an autoradiogram, and their optical density ratios were compared by 2-by-2 (paired vs unpaired and 25 vs 50 trials) analysis of variance. Those brain structures were of 2 types; the first type showed similar changes of 2-DG uptake in both paired and unpaired groups (Areas 7 and 40 of the cerebral cortex, the habenula and the colliculus inferior), while the second type showed that 2-DG uptake increased in the paired groups but decreased in the unpaired groups (Areas 24, 10, 6, 4 and 3 of the cerebral cortex), as a function of number of trials. Because changes of 2-DG uptake in the first type structures and in Areas 3, 4 and 6 of the second type structures are regarded to reflect learning-nonspecific effects and task- or stimuli-related symmetrical activation, respectively, we concluded that Areas 24 (anterior cingulate cortex) and 10 (prefrontal cortex) were specifically related to conditioned emotional response.

Animals↗
PubMed1991

A study on the brain structures related to conditioned emotional response by means of [14C]2-deoxy-D-glucose method.

Brain structures activated during conditioned emotional response were studied by means of the [14C]2-deoxyglucose method. The experimental (CSE) animals were conditioned with paired 25 25-sec-long flicker sequences (CS) and 1-sec-long 150 V AC electric shocks (US), while the control (CSC) animals were given only 25 CS sequences. Average densities of a unit square (200 microns x 200 microns) of 47 nuclei or cortical areas in the left hemisphere were obtained from an autoradiogram and the optical density ratio (ODR), which is the relative optical density of each structure to that of the corpus callosum, was calculated. Comparison of ODRs of each structure from both groups revealed a significant increased uptake of [14C]2-deoxyglucose (P less than 0.05, Mann-Whitney U-test) in the caudal portion of area 10, area 2, area 18 and the hippocampal formation.

Animals↗
PubMed1990

O2- generation and lipid peroxidation during the oxidation of a glycated polypeptide, glycated polylysine, in the presence of iron-ADP.

Oxidation of glycated polylysine, a model compound of glycated protein, caused O2- production even at physiological pH, which could be accelerated by Fe3(+)-ADP. An enediol structure in glycated polylysine and related compounds, which could be confirmed by I2 uptake, was related to their oxidizability. Glycated polylysine was easily coordinated with Fe3+ even in the presence of phosphate at pH 7.4 and the formation of the iron complex was prevented by desferrioxamine. The exposure of unsaturated phospholipid liposomes to glycated polylysine-Fe3(+)-ADP system caused the production of a thiobarbituric acid-reacting substance, which was completely inhibited by 5 microM alpha-tocopherol or 150 microM desferrioxamine and slightly by 0.5 microM SOD. Catalase (20 micrograms/ml) and 10 mM sodium-benzoate did not affect the iron-glycated polylysine-induced lipid peroxidation, indicating no participation of an OH. in this reaction. A ferrous ion-coordinated glycated polylysine may act as an initiator of phospholipid peroxidation in the presence of oxygen. A possible mechanism of the iron-glycated polylysine-induced lipid peroxidation was discussed.

Adenosine Diphosphate↗
PubMed1990

The ability of granulocytes to generate superoxide anions and hypochlorite during phagocytosis: comparison of neonatal granulocytes with adult granulocytes.

The ability of granulocytes to generate superoxide anions (O2-) and hypochlorite (OCl-) during phagocytosis was investigated using peripheral blood samples from adults and cord blood samples from neonates, using the chemiluminescence probe cypiridina luciferin analog (CLA) for O2- generation and luminol (L) for OCl- generation. OCl- generation by granulocytes was also monitored by taurine chloramine formation. The chemiluminescence probe based upon CLA was highly specific for and sensitive to O2- and could be adopted to determine O2- generation in terms of xanthine oxidase units. The CLA-dependent chemiluminescence by cord blood granulocytes was significantly higher than that by normal adult granulocytes. Taurine chloramine formation was significantly correlated with the L-dependent chemiluminescence (L-CL). Thus, the L-CL is considered to be mainly involved in OCl- generated by phagocytizing granulocytes. L-CLs by cord blood granulocytes and normal adult granulocytes were essentially the same during phagocytosis.

Adult↗
PubMed1988

Mechanism of O2- generation in reduction and oxidation cycle of ubiquinones in a model of mitochondrial electron transport systems.

O2- generation in mitochondrial electron transport systems, especially the NADPH-coenzyme Q10 oxidoreductase system, was examined using a model system, NADPH-coenzyme Q1-NADPH-dependent cytochrome P-450 reductase. One electron reduction of coenzyme Q1 produces coenzyme Q1-. and O2- during enzyme-catalyzed reduction and O2+ coenzyme Q1-. are in equilibrium with O2- + coenzyme Q1 in the presence of enough O2. The coenzyme Q1-. produced can be completely eliminated by superoxide dismutase, identical to bound coenzyme Q10 radical produced in a succinate/fumarate couple-KCN-submitochondrial system in the presence of O2. Superoxide dismutase promotes electron transfer from reduced enzyme to coenzyme Q1 by the rapid dismutation of O2- generated, thereby preventing the reduction of coenzyme Q1 by O2-. The enzymatic reduction of coenzyme Q1 to coenzyme Q1H2 via coenzyme Q1-. is smoothly achieved under anaerobic conditions. The rate of coenzyme Q1H2 autoxidation is extremely slow, i.e., second-order constant for [O2][coenzyme Q1H2] = 1.5 M-1.s-1 at 258 microM O2, pH 7.5 and 25 degrees C.

Anaerobiosis↗
PubMed1988

A new and suitable reconstructed system for NADPH-dependent microsomal lipid peroxidation.

In order to evaluate the O-2 participation in NADPH-dependent microsomal lipid peroxidation, we used reconstructed system which contained detergent-solubilized NADPH-dependent cytochrome P-450 reductase, cytochrome P-450, phospholipid liposomes, NADPH and Fe3+-ADP. Lipid peroxidation, monitored by the formation of thiobarbituric acid-reactive substance, was increased with increasing concentration of detergent-solubilized NADPH cytochrome P-450 reductase, cytochrome P-450 or Fe3+-ADP. Cytochrome P-450-dependent lipid peroxidation was parallel to O-2 generation monitored by chemiluminescence probe with 2-methyl-6-(p-methoxyphenol)-3,7-dihydroimidazo[1,2-a]pyrazin++ +-3-one. Lipid peroxidation was significantly inhibited by superoxide dismutase, but not by catalase or sodium benzoate. The reconstructed system herein described is considered to be very close to NADPH-dependent microsomal lipid peroxidation system.

Animals↗
PubMed1988

Properties of a coenzyme, pyrroloquinoline quinone: generation of an active oxygen species during a reduction-oxidation cycle in the presence of NAD(P)H and O2.

The oxidation of NAD(P)H by pyrroloquinoline quinone (PQQ) was non-enzymatically carried out at physiological pH in the presence of O2. The PQQ-NAD(P)H system requires about 1 mol of O2 for the oxidation of 1 mol of NAD(P)H. The oxidation of NAD(P)H occurred at a pseudo-first-order rate with respect to NAD(P)H and was of zero order with respect to PQQ concentration in in the presence of O2: k0[PQQ] [NAD(P)H] = k1 [NAD(P)H], where k0[PQQ] = k1, in which [PQQ] represents the initial concentration of PQQ. k0 values for NADH and NADPH were 3.4.10(2) M-1.min-1 and 2.0.10(2) M-1.min-1, respectively, at 25 degrees C and at 258 microM O2 (initial concentration). The system produced O-2, probably by the interaction of PQQ.H and/or NAD(P).with O2, during the oxidation of NAD(P)H. PQQH2 and PQQ.H were easily oxidized to PQQ in the presence of O2, yielding H2O2.

Coenzymes↗