摘要:

AbstractNeurology manuals generally recommend odor identification for simple assessment of olfaction. Nevertheless, even patients with normal olfaction (normosmics) often perform only poorly. Three experiments demonstrate that such an ambiguous outcome will disappear if the test incorporates highly familiar substances and, more important, a procedure to circumvent the olfactory-verbal gap that frequently separates an odor from its name. One multiple-choice procedure, for instance, led to 100% accuracy among normosmics. Another led to 99% accuracy among normosmics and 0% accuracy among anosmics. The investigation also reveals that scratch-and-sniff labels could possibly replace customary odorants in the clinical test.

ISSN:0161-6412    

DOI:10.1080/01616412.1979.11739536

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractA micropressure transducer (sensitive to 0.1 cm H2O) utilizing a manual servo nulling system and a micropipette (tip diameter 12–20μm) was designed in order to measure endolymphatic and perilymphatic hydrostatic pressures in the inner ear of the guinea pig. Perilymphatic pressures were measured through the round window membrane in animals in which the ossicular structures had been removed and in those in which the middle ear structures were intact. Endolylnphatic pressures were measured after removal of the middle ear structures. There was a significant (p<0.001) difference between perilymphatic pressures in the presence (4.7±0.36 cm H20) and absence (2.43±0.22 cm H20) of the middle ear structures. The endolymphatic pressure was 0.00 cm H20 when measured through the basilar membrane after disruption of the scala tympani, and was 3.34±0.57 when monitored through the spiral ligament and stria vascularis. In order to verify the accuracy of these measurements, we monitored pressures in animals whose perilymphatic pressures were artificially maintained by an external source. Recoveries were always 95–100% of the artificially applied pressure. The injection of purified cholera toxin into the scala media through the basilar membrane resulted in a significant (p<0.001) increase in endolymphatic pressure.

ISSN:0161-6412    

DOI:10.1080/01616412.1979.11739537

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractMetallic cobalt and aluminum rods were implanted into the cerebral cortices of rats. Almost all the animals with cobalt implantation were found to be epileptic 30 days after the operation. Tissue samples from the cerebral cortices were sampled for electron microscopy. The most significant changes in the cobalt-implanted animals were the disintegration of the rough endoplasmic reticulum in many cortical neurons and the accumulation of neurofilaments within the perikaryon. Such filamentous accumulation was usually found near the perinuclear position, at the periphery of the neurons, and in areas where there was a paucity of regular rough endoplasmic reticulum. Large aggregates of SER-like tubulovesicular structures were also found within many neuronal processes. Some of these neuronal processes could be identified to be postsynaptic dendritic terminals. Large nuclear pseudoinclusions consisting of cytoplasmic materials were also found in some cortical neurons. These ultrastructural changes could also be occasionally observed in the opposite (cobalt-free) hemisphere of the brain (mirror image) in the cobalt-implanted animals. However, the brains of the aluminum-implanted or blank-control animals were free from any of these changes.

ISSN:0161-6412    

DOI:10.1080/01616412.1979.11739538

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractA method of measuring cerebral blood flow during neurosurgery is described. It is an adaptation of the standard133Xe intravenous injection method, with computation restricted to data collected over the first 3 min. In addition to a theoretical presentation of the method and an analysis of the effect of residual133Xe activity when sequential runs are performed in close approximation, the technique is validated experimentally by comparison with intracarotid133Xe injection in baboons.

ISSN:0161-6412    

DOI:10.1080/01616412.1979.11739539

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractClinical studies indicate that early epilepsy after head injury may be associated with some transient and reversible pathophysical processes of the brain. It has been proposed that epileptogenesis in the neocortex and hippocampus may be related to potassium ion accumulation in extracellular spaces. To investigate this hypothesis, we measured [K+]0using potassium-sensitive microelectrodes in the sensorimotor cortex of cats during early seizures induced by trauma.The [K+]0increases associated with seizure activity ranged from 14.6 to 25.1 mM, and these were significantly higher than those unassociated with spikes or seizure discharges. Moreover, high K+solutions (15 mMor more) directly applied to the cortex produced spiking and seizures. These results seem to support the hypothesis that accumulation of [K+]0is related to development of early epilepsy.

ISSN:0161-6412    

DOI:10.1080/01616412.1979.11739540

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractIn cerebral ischemia, brain oxygen supply is totally exhausted within seconds. This necessitates cessation of mitochondrial electron transfer and energy (ATP) production. After certain periods of ATP deficiency of from 5 to 90 min, irreversible damage of mitrochondrial membranes occurs. This results in decreased mitochondrial function, characterized by inhibited State 3 respiratory rates, low respiratory control ratios, and inhibited Ca2+transport activities. A 30-min recirculation period of the ischemic brain tissue induces total restitution of mitochondrial respiratory capacity after complete ischemia, but not after incomplete ischemia. Regional in situ measurements of brain pyridine nucleotide redox levels, tissue ATP, and lactate concentrations indicate variable metabolic responses of different brain regions to oligemia. Macroheterogeneity from region to region, as well as microheterogeneity within a region, are demonstrated.Contrary to the effects of tissue ischemia involving reduced or zero cerebral blood flow and tissue oxygenation, sublethal hypoxia alone at normal or increased levels of blood flow induces adaptation of the mitochondrial enzyme system to a new level of respiratory capacity, without any indications of inhibited mitochondrial energy production. Acute hypoxia induces increased respiratory capacities within 30–60 min. Under chronic conditions, alterations of mitochondrial cytochrome concentrations accompany the increased respiratory capacities. Instead of the decreased efficiency of mitochondrial energy-producing mechanisms induced by ischemia, hypoxia induces increased efficiency of energy production.

ISSN:0161-6412    

DOI:10.1080/01616412.1979.11739541

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractIntraluminal diameter measurements of the branches of the middle cerebral artery were taken from 50 adult human cerebral hemispheres of a routine autopsy service. The measurements were confined to the cortical branches found on the surface of the brain located over the lateral hemisphere, with the center at the transverse gyrus of Heschl and extending over the circular portion of the brain, with a diameter of approximately 6 cm. It was hoped that these measurements would assist in the appropriate choice of artery for microanastomosis in the superficial temporal artery bypass procedure, now being done for enhancement of cortical perfusion.

ISSN:0161-6412    

DOI:10.1080/01616412.1979.11739542

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractTreatment with varying doses of morphine and its antagonist naloxone produced different response patterns in“spontaneous”multiunit discharges recorded from the medial thalamus and caudate nucleus of freely behaving rats previously implanted, stereotaxically, with permanent semimicroelectrodes. The changes in electrical discharges induced by incremental doses of morphine exhibited dose-related patterns, and could be reversed by naloxone. This procedure, testing several incremental doses of a drug, provides a tool with which to identify and classify the specific response patterns induced by morphine. The two structures examined in the present study exhibited four response patterns to the treatments but only one pattern of response was similar in the two nuclei. The medial thalamic units are more sensitive to morphine than those recorded from the caudate nucleus. The present finding, i.e., acute effects of morphine, provides basic information with which to examine the physiological properties underlying the chronic effects of morphine.

ISSN:0161-6412    

DOI:10.1080/01616412.1979.11739543

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractThis paper summarizes the work of developing and analyzing a mathematical model of schizophrenia. First the psychological and physiological studies of patients with periodic catatonia made by R. R. Gjessing are briefly described. Then a mathematical model, which is based on Gjessing’s work and consists of a set of nonlinear ordinary differential equations, is derived. Gjessing showed that there was a periodic change in the basal metabolic rate associated with a periodic change in the symptoms of catatonia. This suggests a study of the thyroid control system, and since the thyroid control system is a negative feedback system, previous engineering studies are followed and a system of ordinary differential equations is used as a model. The first such model was due to Danziger and Elmergreen, and their model and improvements of their model are described. Then the models are analyzed qualitatively and the mathematical results are interpreted medically. Solutions of the system of differential equations corresponding to a stable set of symptoms in the schizophrenic patients, solutions corresponding to periodic patterns of symptoms (periodic catatonia), and solutions corresponding to random or unpredictable patterns of symptoms are obtained. The model suggests that since certain parameters are varied, various types of solutions and hence various patterns of symptoms are obtained. There are a number of unresolved questions in this study, and these problems are discussed in detail as they arise.

ISSN:0161-6412    

DOI:10.1080/01616412.1979.11739544

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor