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S Kogure

Publications and source records attributed to S Kogure.

50 records · Page 3Linked to original sources
PubMed1983

Response characteristics of lateral hypothalamic neurons to odors in unanesthetized rabbits.

Extracellular responses of 103 neurons to eight odors were studied in the lateral hypothalamic area (LHA) of unanesthetized rabbits. In response to electrical stimulation of the olfactory bulb (OB), 97 units were excited with latencies of 3.7-68.0 ms (mean, 19.4 ms) and the activity of 6 units was suppressed. In the LHA, 90 units of 103 were found that responded to from one to eight odors. The number of units that responded to three odors was the most numerous (22%) among these odor-sensitive units. Lateral hypothalamic (LH) neurons showed high response probabilities to cineole (0.72), cyclotene (0.68), and isovaleric acid (0.54). Of the recorded units, 94% showed an excitatory-type response to both electrical stimulation of the OB and odor stimuli of the olfactory mucosa, while only 6% showed an inhibitory-type response to both stimuli. These results suggest that the olfactory effect on the LHA is predominantly excitatory. Responses to a concentration series of odors were examined in 24 LH neurons. In most cases, response intensity did not increase monotonically with increasing odor concentration. Instead, the concentration-response curves of most units showed a peak or inflections during the concentration series. Compared with results obtained from other olfactory structures in different species, it appears that LH neurons do not contribute much to odor discrimination in rabbits.

Animals↗
PubMed1981

Alterations of circulatory responses to upright tilt in cardiac patients.

Circulatory responses to the upright tilt were studied in 20 normal subjects and 27 cardiac patients with ischemic heart disease or idiopathic cardiomyopathy. In normal subjects, the upright tilt caused obvious increases in heart rate and diastolic pressure, a slight decrease in systolic pressure and marked decreases in cardiac output and stroke volume. The circulatory changes during the tilt were less pronounced in the cardiac patients as compared with the normal subjects. The reductions of cardiac output and stroke volume and the increase in total peripheral resistance were all significantly diminished. A paradoxical increase in cardiac output during the tilt, an observation hitherto not well recognized, was observed in 5 cases with low cardiac index during the control period. Although several possibilities can be considered for the explanation of the diminished, sometimes paradoxical, circulatory responses to the tilt in cardiac patients, the improvement of the function of the diseased heart by preload reduction was proposed as an important factor. There was a significant negative correlation between the per cent changes of cardiac output and the per cent changes of PEP/LVET. It was suggested that the measurements of systolic time intervals during the tilt might be useful for evaluating the severity of the hemodynamic derangement in cardiac patients.

Adolescent↗
PubMed1980

A transthalamic olfactory pathway to orbitofrontal cortex in the monkey.

1. Evoked potentials restricted to the magnocellular portion of the mediodorsal nucleus (MDmc) of the thalamus were recorded after stimulation of the olfactory bulb (OB) and the posterior orbital cortex of the frontal lobe (OFC). Potentials evoked by stimulation of OB were probably trans-synaptically elicited, while potentials evoked by stimulation of OFC were probably a result of antidromic activation. 2. The area in which stimulation could elicit antidromic evoked potentials in MDmc was located in the centroposterior portion of OFC (CPOF). This area corresponds approximately to Walker's (80) area 13 and to von Bonin and Bailey's (9) area FF, and is situated medial and just anterior to a previously identified olfactory area, the lateroposterior portion of OFC (LPOF), which receives olfactory impulses through the hypothalamus. 3. Using extracellular microelectrodes, 58 neurons that responded with short latencies to OFC stimulation were identified in MDmc. To determine whether these neurons were activated antidromically by CPOF stimulation, three conventional neurophysiological criteria were applied; 20 of 58 neurons satisfied all the three criteria. Hence, they were concluded to be thalamocortical relay (TCR) neurons. 4. Intracellular recording of MDmc neurons disclosed that CPOF stimulation elicits an antidromic spike potential accompanied by an afterhyperpolarization. This hyperpolarization was presumed to be due to concurrent stimulation of inhibitory orbitothalamic fibers. It was also shown that EPSP-like depolarizations with superimposed spike potentials often occurred in the middle of the afterhyperpolarization. 5. Intracellular recording of MDmc neurons strongly suggested that the remaining 38 neurons that did not satisfy one of the three criteria were also TCR neurons. 6. These studies provide electrophysiological evidence for a transthalamic olfactory pathway from OB through MDmc to CPOF. 7. Using an extracellular recording technique, responses of neurons to eight odors were examined in CPOF and MDmc of unanesthetized awake monkeys. When these results were compared with the responses of neurons to the same odors in OB, prepyriform-amygdaloid area, and LPOF, it was concluded that the newly found transthalamic olfactory pathway to CPOF is very different in function from the previously demonstrated transhypothalamic olfactory pathway to LPOF.

Animals↗
PubMed1979

[8-Quinolinol-5-sulfonic acid-loaded resin as a preconcentrating agent in the neutron activation analysis of the chalcophile elements (author's transl)].

A chelating agent-loaded resin consisting of 8-quinolinol-5-sulfonic acid and an anion-exchange resin (HOx-resin) was prepared in order to concentrate trace chalcophile elements in natural water samples selectively before neutron activation analysis. The exchange capacity of the Diaion SA No. 100 for the reagent (1.8 meq . g-1 resin) corresponds approximately to that for chloride ion (1.83 meq . g-1 resin), indicating that 8-quinolinol-5-sulfonic acid is adsorbed quantitatively on the exchange site of the resin through the sulfonate anion in the reagent. The basic conditions for the adsorption of the metal ions on the resin were investigated by employing the column method. The nitrate concentration and the pH of the sample solution affect the adsorption behavior of metal ions. Several solutions containing metal ions with varying pH or varying nitrate concentration were applied to the resin column (35 mm x 7 mm phi) with a flow rate of 2.0 cm3 . min-1. As a result, the optimum conditions for the quantitative adsorption of copper(II), zinc(II), cadmium(II), cobalt(II), nickel(II) and manganese(II) were as follows: NO3- less than 0.01 mol . dm-3 pH greater than 4.6. Furthermore, the feasibility of the above conditions as well as quantitative adsorption of the chalcophile elements was confirmed through the neutron activation analysis of the synthesized metal solutions.

Activation Analysis↗
PubMed1978

Clinical analysis of colour vision deficiencies with The City University test.

The City University colour vision test (CUCVT) was used for the examination of 158 subjects suffering from congenital colour vision defects (36 protanopes, 122 deutanopes) and its results were compared with that of an anomaloscope and of the panel D-15. 23% of the subjects classified as protanopes and 98% of the subjects classified as deuteranopes by means of the anomaloscope were also classified as such by means of the CUCVT, while 93% of the subjects classified as protanomalous and 90% of the subjects classified as deuteranomalous by means of the anomaloscope gave normal answers at the CUCVT. The results of the CUCVT were almost the same as with panel D-15 except protanopia. The colour spots of each plate of the CUCVT were plotted on a CIE chromaticity diagram and the results of this study are also reported.

Adolescent↗
PubMed1978

Clinical experience with the Lovibond Colour Vision Analyser. Results from the examination of normal and congenital colour-deficient subjects.

The Colour Vision Analyser was used for testing 98 persons of both sexes, aged from 10 to 70 years, and recognized as normal by means of pseudo-isochromatic plates and an anomaloscope. A drop of the saturation thresholds from yellow to green and from blue to purple was observed from the age of 40 years. The saturation thresholds from yellow to green was found lower in every age group than that from blue to purple. Congenital colour defects could be completely distinguished from normal subjects. As for the classification in types, those diagnosed as deutan by means of the anomaloscope were also diagnosed as deutan by the Analyser, however, there were, among those diagnosed as protan by the anomaloscope, some subjects who were diagnosed as deutan by the Analyser. Nearly all cases could be classified as anopia or anomaly.

Adolescent↗
PubMedDate not supplied

Effect of decreased retinal illumination on frequency doubling technology.

PURPOSE: To investigate the effect of changes in retinal illumination on Frequency Doubling Technology (FDT). METHODS: Five eyes, of 5 adults who were free from identifiable ocular pathology, were examined using the Snellen chart and the Pelli-Robson chart, conventional automated perimetry, and the full threshold N-30 program of FDT. Each test was performed with and without a 0.9, 1.5, or 2.4 log unit neutral-density (ND) filter placed before the eye. Furthermore, the influence of pupil diameter on FDT test results was compared after treatment with pilocarpine or cyclopentolate with the influence of ND filters. RESULTS: All tests showed a decrease in sensitivity with decreasing retinal illumination. Frequency Doubling Technology showed an especially pronounced and significant decrease in sensitivity. The maximum mean threshold difference in FDT results with ND filter was 31.2 dB while that with the Humphrey Field Analyzer and the Pelli-Robson chart were 13.3 dB and 0.66 log contrast, respectively. The mydriatic state of the pupil increased the sensitivity of FDT and the miotic state decreased it to about the same extent as the the 0.9 ND filter. CONCLUSION: The change in retinal illumination has more impact on FDT than on spatial contrast tests and conventional automated perimetry. It is important to take this into account in evaluating FDT results.

Adaptation, Ocular↗
PubMedDate not supplied

A new parameter for assessing the thickness of the retinal nerve fiber layer for glaucoma diagnosis.

PURPOSE: To investigate a new method for assessing the thickness of the retinal nerve fiber layer thickness (NFLT) for glaucoma diagnosis, using scanning laser polarimetry. MATERIAL AND METHODS: Thirty eyes of thirty patients with ocular hypertension or glaucoma were examined using a scanning laser polarimeter. NFL T was measured in each of four 90-degree quadrants; superior (S), temporal (T), inferior (I) and nasal (N) along 1.5-disc diameters concentric from the disc margin. The new parameters S-N (meaning the thickness of the superior nerve fiber layer over the nasal one) etc. were compared with the conventional parameters (S, S/N, etc.). The correlations between these parameters and the mean threshold of the associated visual field test points were included in the comparison. RESULTS: The total thickness (sum of S, I, N and T), N and T did not correlate to the visual field, but S and I did. The new parameters were well correlated to the visual field, S-N giving the best correlation coefficient (rs = O. 782, p < O.0001), and sensitivity and specificity (the area under the receiver operating characteristic curves was 0.91). CONCLUSIONS: The nasal NFLT was the smallest part of individual variation and glaucomatous damage. The new parameters, based on the nasal NFLT, were good evaluators of the changes in glaucoma.

Adult↗