共查询到20条相似文献,搜索用时 15 毫秒
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D R Kostreva E J Zuperku G L Hess R L Coon J P Kampine 《Journal of applied physiology》1975,39(1):37-40
This study in mongrel dogs, anesthetized with sodium pentobarbital, verified the existence of pulmonary receptors whose afferents traverse the right and left upper thoracic white rami communicantes. These receptors responded to lung inflation as well as pinching of the lung parenchyma and were nonadapting in nature. In some fibers, increases in afferent activity were also observed when the pulmonary artery and veins were mechanically stimulated by probing. Conduction velocities of these afferents were measured in single-fiber preparations and were of the Adelta fiber type. 相似文献
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Dan-Thanh T. Nguyen Melissa J. Blacker James A. Goodchild 《Invertebrate neuroscience : IN》2012,12(2):139-146
Whilst many classes of insecticides target the insect central nervous system (CNS), their effects in the CNS of pest aphids have not been demonstrated. In this report, we describe an electrophysiological method for recording spontaneous neuronal activity from the giant willow aphid (Tuberolachnus salignus). Using extracellular recording electrodes and two analysis methods (threshold and template search), spontaneous spike activity was shown to exhibit sensitivity to the neuroexcitatory insecticide imidacloprid. This method allows changes in the frequency of action-potentials to be monitored during direct bath exposure to chemical agents, enabling a means of assessing and comparing neurotoxic effects of insecticides in a previously inaccessible superfamily of pest insects. 相似文献
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Skin surface cooling improves orthostatic tolerance through a yet to be identified mechanism. One possibility is that skin surface cooling increases the gain of baroreflex control of efferent responses contributing to the maintenance of blood pressure. To test this hypothesis, muscle sympathetic nerve activity (MSNA), arterial blood pressure, and heart rate were recorded in nine healthy subjects during both normothermic and skin surface cooling conditions, while baroreflex control of MSNA and heart rate were assessed during rapid pharmacologically induced changes in arterial blood pressure. Skin surface cooling decreased mean skin temperature (34.9 +/- 0.2 to 29.8 +/- 0.6 degrees C; P < 0.001) and increased mean arterial blood pressure (85 +/- 2 to 93 +/- 3 mmHg; P < 0.001) without changing MSNA (P = 0.47) or heart rate (P = 0.21). The slope of the relationship between MSNA and diastolic blood pressure during skin surface cooling (-3.54 +/- 0.29 units.beat(-1).mmHg(-1)) was not significantly different from normothermic conditions (-2.94 +/- 0.21 units.beat(-1).mmHg(-1); P = 0.19). The slope depicting baroreflex control of heart rate was also not altered by skin surface cooling. However, skin surface cooling shifted the "operating point" of both baroreflex curves to high arterial blood pressures (i.e., rightward shift). Resetting baroreflex curves to higher pressure might contribute to the elevations in orthostatic tolerance associated with skin surface cooling. 相似文献
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D H Silber L I Sinoway U A Leuenberger V E Amassian 《Journal of applied physiology》2000,88(1):126-134
Single-pulse magnetic coil stimulation (Cadwell MES 10) over the cranium induces without pain an electric pulse in the underlying cerebral cortex. Stimulation over the motor cortex can elicit a muscle twitch. In 10 subjects, we tested whether motor cortical stimulation could also elicit skin sympathetic nerve activity (SSNA; n = 8) and muscle sympathetic nerve activity (MSNA; n = 5) in the peroneal nerve. Focal motor cortical stimulation predictably elicited bursts of SSNA but not MSNA; with successive stimuli, the SSNA responses did not readily extinguish (94% of discharges to the motor cortex evoked SSNA responses) and had predictable latencies [739 +/- 33 (SE) to 895 +/- 13 ms]. The SSNA responses were similar after stimulation of dominant and nondominant sides. Focal stimulation posterior to the motor cortex elicited extinguishable SSNA responses. In three of six subjects, anterior cortical stimulation evoked SSNA responses similar to those seen with motor cortex stimulation but without detectable movement; in the other subjects, anterior stimulation evoked less SSNA discharge than that seen with motor cortex stimulation. Contrasting with motor cortical stimulation, evoked SSNA responses were more readily extinguished with 1) peripheral stimulation that directly elicited forearm muscle activation accompanied by electromyograms similar to those with motor cortical stimulation; 2) auditory stimulation by the click of the energized coil when off the head; and 3) in preliminary experiments, finger afferent stimulation sufficient to cause tingling. Our findings are consistent with the hypothesis that motor cortex stimulation can cause activation of both alpha-motoneurons and SSNA. 相似文献
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Spontaneous electrical activity and effects of noradrenaline on pregnant human myometrium recorded by the single sucrose-gap method 总被引:1,自引:0,他引:1
Spontaneous intracellular electrical activity and contraction of pregnant human myometrium were recorded by the single sucrose-gap method, and the effects of noradrenaline on the muscle were studied. Human myometrium obtained at various stages of gestation showed three types of action potentials, which were spike-, plateau- and intermediate-type in configuration. In human isthmic myometrium at full-term pregnancy dissected from the endometrial side of the uterine wall, both plateau and spike types of action potential were observed. All contractions were well synchronized with each action potential. These results indicate the possibility of the intertwinning of two different types of muscle bundles. The magnitude of contraction depended on the frequency of the spikes in spike-type or the plateau duration in plateau-type action potentials. The alpha-excitatory action of noradrenaline (2 X 10(-7) g/ml) was found to affect the configuration of the action potential; even the spike-type configuration became plateau. 相似文献
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Electrical responses of the fenestra cochleae to stimulation by clicks of different intensity, polarity, and frequency, were studied in anesthetized cats. The absolute values of amplitude and latent period of the neural component of the response reflect the physiological state of the auditory nerve. Besides ordinary potentials characterized by peaks N1 and N2, specific responses were observed when clicks with an intensity of 85 dB or "rarefaction" clicks were used. Dependence of the amplitude of these responses on the intensity of acoustic stimuli of different polarity was investigated during a change in the rhythm of the stimulation; the effect of different rhythms of stimulation on the gradient of the curve reflecting this relationship was examined. The possible mechanisms of the effect of stimulus frequency are discussed.Scientific-Research Institute of Otolaryngology, Ministry of Health of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 11, No. 2, pp. 151–157, March–April, 1979. 相似文献
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Herbert A. Pohl 《Journal of bioenergetics and biomembranes》1981,13(3-4):149-169
Electrical oscillatory rf phenomena are present during the division of cells. These were examined by studying the attraction of cells for polarizable powders. They are understood to occur by a process termed microdielectrophoresis (-DEP), the motion induced by a nonuniform electric field acting on a polarizable body. The suggestion that an electrical oscillatory aspect may also be involved in the contact or density inhibition of cell division and the mechanisms that may cause invasiveness of oncogenic cells are theoretically explored (i.e., changes in either the power level or the frequency of the oscillatory phenomena associated with cell division, or in the degree of electrical insulation of the cell from electrical damping by nearby cells). A number of experiments to test this hypothesis are suggested. 相似文献
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Cui J Sathishkumar M Wilson TE Shibasaki M Davis SL Crandall CG 《American journal of physiology. Heart and circulatory physiology》2006,290(4):H1601-H1609
Skin sympathetic nerve activity (SSNA) exhibits low- and high-frequency spectral components in normothermic subjects. However, spectral characteristics of SSNA in heat-stressed subjects are unknown. Because the main components of the integrated SSNA during heat stress (sudomotor/vasodilator activities) are different from those during normothermia and cooling (vasoconstrictor activity), we hypothesize that spectral characteristics of SSNA in heat-stressed subjects will be different from those in subjects subjected to normothermia or cooling. In 17 healthy subjects, SSNA, electrocardiogram, arterial blood pressure (via Finapres), respiratory activity, and skin blood flow were recorded during normothermia and heat stress. In 7 of the 17 subjects, these variables were also recorded during cooling. Spectral characteristics of integrated SSNA, R-R interval, beat-by-beat mean blood pressure, skin blood flow variability, and respiratory excursions were assessed. Heat stress and cooling significantly increased total SSNA. SSNA spectral power in the low-frequency (0.03-0.15 Hz), high-frequency (0.15-0.45 Hz), and very-high-frequency (0.45-2.5 Hz) regions was significantly elevated by heat stress and cooling. Interestingly, heat stress caused a greater relative increase of SSNA spectral power within the 0.45- to 2.5-Hz region than in the other spectral ranges; cooling did not show this effect. Differences in the SSNA spectral distribution between normothermia/cooling and heat stress may reflect different characteristics of central modulation of vasoconstrictor and sudomotor/vasodilator activities. 相似文献
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V. P. Lyashenko O. Z. Mel’nikova A. V. Gorkovenko S. M. Lukashov T. G. Chaous 《Neurophysiology》2007,39(1):64-75
We examined the dynamics of the spectral powers and indices of frequency components of background field electrical activity
recorded from tropho-and ergotropic zones of the rat hypothalamus (electrohypothalamogram, EHtG) in the course of long-term
(21 weeks) emotional stress induced by a zooconflict situation. Low-frequency delta-range (0.5 to 3.5 Hz) oscillations dominated
in EHtGs recorded from both hypothalamic zones of both control and stressed animals. The integral power of EHtG oscillations
underwent significant changes within the observation period; it considerably increased on the 6th to 9th week, dropped within
the 12th to 18th week, and, after this (up to the 21st week) again increased, i.e., the dynamics, in general, were threephase.
The dynamics of the power of separate frequency components of EHtG showed certain similarities to the dynamics of the integral
power. Changes in the EHtG power in stressed animals were characterized by a shorter duration and greater rate; the powers
of all EHtG components in these animals were lower than in control ones within a greater part of the observation period. The
dynamics of the normalized powers and of the indices of different EHtG rhythms in stressed and control animals, especially
the dynamics of dominating oscillations of the delta and theta ranges, were to a certain extent opposite. Our data show that
changes in the EHtG can be electrographic correlates of subsequent phases of a long-lasting stress reaction of the organism
in the course of the experiment; specific features of manifestation of these modifications in the tropho-and ergotropic hypothalamic
zones are related to a certain specificity of the hormonal/transmitter mechanisms in the structures under study.
Neirofiziologiya/Neurophysiology, Vol. 39, No. 1, pp. 69–80, January–February, 2007. 相似文献
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Jochen Probst Sonja Brechtel Birgit Scheel Ingmar Hoerr Günther Jung Hans-Georg Rammensee Steve Pascolo 《Genetic vaccines and therapy》2006,4(1):1-9
The rapid degradation of ribonucleic acids (RNA) by ubiquitous ribonucleases limits the efficacy of new therapies based on RNA molecules. Therefore, our aim was to characterize the natural ribonuclease activities on the skin and in blood plasma i.e. at sites where many drugs in development are applied. On the skin surfaces of Homo sapiens and Mus musculus we observed dominant pyrimidine-specific ribonuclease activity. This activity is not prevented by a cap structure at the 5'-end of messenger RNA (mRNA) and is not primarily of a 5'- or 3'-exonuclease type. Moreover, the ribonuclease activity on the skin or in blood plasma is not inhibited by chemical modifications introduced at the 2'OH group of cytidine or uridine residues. It is, however, inhibited by the ribonuclease inhibitor RNasin® although not by the ribonuclease inhibitor SUPERase· In?. The application of our findings in the field of medical science may result in an improved efficiency of RNA-based therapies that are currently in development. 相似文献
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Dan'ko SG 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》2000,50(5):884-888
The EEG and infraslow phasic electrical processes in the band of 0.05-0.5 Hz (ISPP) were simultaneously recorded in 16 derivations (10-20 System without Fz, Cz, and Pz) in 35 women volunteers in the state of quiet wakefulness with closed eyes. Artifacts and non-stationary segments with a sharp amplitude increase were eliminated from the records in preprocessing editing. Spatial correlations were evaluated using maxima of crosscorrelation functions and coherence functions averaged over the whole spectrum. Correlations for both kind of processes appeared to be rather similar, in particular, they were both characterized by the low values if interhemispheric covariations in the temporal areas. The ISSP correlations were significantly lower for the least distance between derivations and had lower spatial gradient than the EEG correlations. There were also some topical differences between the processes. The obtained evidence support the idea of the ISPP as direct manifestations of cortical electrical activity, however, rather specific in relation with the routine EEG correlations. 相似文献