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  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Annals of noninvasive electrocardiology 3 (1998), S. 0 
    ISSN: 1542-474X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: As the duration of the Q-T interval is dependent upon the length of the preceding cardiac cycle, changes in QT interval duration mainly reflect, in normal subjects, the physiological beat-by-beat variability of the sinus node. However, little information is available on short-term Q-T variability in patients with an abnormal neural modulation of the sinus node.Methods: We analyzed, with autoregressive techniques, RR and R-Tapex, and R-Tend variabilities in 12 patients after myocardial infarction, in 13 patients before and after percutaneous transluminal coronary angioplasty (PTCA), and in 10 age-matched controls.Results: No significant differences in mean value and variance of RR, R-Tapex, and R-Tend interval among the three groups of subjects were observed. Spectral analysis of RR variability was characterized by signs of sympathetic activation with a predominance of low frequency (LF) component in patients after myocardial infarction (69 ± 5 nu) and before PICA (74 ± 5 nu) in comparison to controls (50 ± 4 nu). Instead, spectral energy was equally distributed within LF and HF (high frequency) components of RTapex and R-Tend variabilities in the three groups of subjects.Conclusions: These data indicate that the predominance of LFRR in normalized units, indicating an increase of sympathetic modulation of sinus node activity in patients with coronary artery disease, are not accompanied by a parallel predominance of the LF component of R-Tapex and R-Tend variabilities. This difference reflects, in our opinion, a minor dependency of duration of ventricular repolarization from the preceding cardiac cycle in patients with coronary artery disease.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 783 (1996), S. 0 
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 206 (1965), S. 627-629 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Recent investigations which we have carried out3,4 on the distribution of somatically evoked potentials throughout the so-called 'non-specific' sensory system in the core of the brain5,6 (several components of which are known to be organized in largely 'open' nuclei1) have shown that some of these ...
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 28 (1972), S. 269-270 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Résumé Nous avons enregistré dans les nerfs sympathiques la décharge de fibres afférentes isolées provenant de chacune des cavités cardiaques. Cette décharge était en rapport avec les événements hémodynamiques qui avaient lieu dans la cavité innervée par chaque fibre. Cette voie afférente à la moelle épinière pourrait bien contribuer au contrôle nerveux de la circulation.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 26 (1970), S. 965-966 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Résumé La décharge de fibres sympathiques préganglionnaires isolées, faisant probablement partie de l'innervation efférente du cœr, a été étudiée sur des chats spinalisés et vagotomisés par rapport à des augmentations de la tension artérielle provoquées mécaniquement ou pharmacologiquement. Les réponses obtenues consistaient soit en une diminution soit en une augmentation de la décharge sympathique, le genre de réponse étant constant pour chaque fibre, et de nature réflexe.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 27 (1971), S. 1423-1424 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Résumé La décharge de fibres vagales d'origine cardiaque est augmentée au cours d'une réduction du flux sanguin dans l'artère coronaire de gauche. Toutefois cette excitation n'a lieu que lorsque le coeur est déjà défaillant à cause de l'ichémie. La stimulation effective paraît être de nature mécanique.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Acta neurochirurgica 12 (1964), S. 198-214 
    ISSN: 0942-0940
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die afferente Modulation des zentralnervösen Mechanismus, der das bewußte Verhalten reguliert, wird besprochen und mit den Wirkungen verglichen, die durch afferente und Hirnstammreizung auf das emotionale Verhalten diencephaler Herkunft auszulösen sind. Die elektroencephalographische Synchronisation und der Schlaf, die durch Reizung der Druckrezeptoren des Sinus caroticus am „encéphale isolé“ oder am intakten Tier hervorgerufen werden, werden in Parallele gesetzt zur Hemmung der spontanen Ausbrüche von Scheinwut (sham rage) bei dekortizierten Katzen, die durch natürliche Reizung der Druckrezeptoren verursacht wird; anderseits bewirken die Chemorezeptoren des Carotis-Sinus-Knotens nicht nur eine Weckreaktion, sondern sind auch in der Lage Anfälle von Scheinwut bei der dekortizierten Katze hervorzurufen. So wie beim „encéphale isolé“ und intakten Tier Reizungen des reticulären Systems zu verschiedenen Zeiten entweder Desynchronisation und Weckung oder Synchronisation und Schlaf bewirken, so können Wutanfälle durch elektrische Reizung innerhalb der Formatio reticularis sowohl hervorgerufen als auch gehemmt werden. Schließlich hängt das Wutverhalten der dekortizierten Katze ebenso wie die corticale Desynchronisation und Wachheit des intakten Tieres vom tonisierenden Untergrund der aufsteigenden reticulären Aktivität ab. Vermutlich beeinflussen gleichartige oder nahe verwandte Mechanismen sowohl das bewußte, wache Verhalten als auch verschiedene somatische und viscerale Funktionen, beispielsweise diejenigen, die vom emotionalen Verhalten abhängig sind.
    Abstract: Résumé La modulation afférente des mécanismes nerveux centraux responsables du comportement conscient est comparée aux effets de l'excitation afférente et du tronc cérébral sur le comportement émotionnel d'origine diencéphalique. L'excitation des barorécepteurs du sinus carotidien dans la préparation «encéphale isolé» ou sur les animaux intacts produit synchronisation électroencéphalographique et sommeil, et chez le chat décortiqué elle produit inhibition des accès spontanés de colère. Par ailleurs les chémorécepteurs du corpuscule carotidien n'ont pas seulement une action de réveil, ils sont également capables de déclencher des accès de colère chez le chat décortiqué. Dans la préparation «encéphale isolé» et sur les animaux intacts, des stimulations réticulaires différentes peuvent entraîner soit une désynchronisation électroencéphalographique et le réveil, soit par contre une synchronisation et le sommeil. Chez le chat décortiqué les accès de colère peuvent être soit provoqués, soit arrêtés par l'excitation électrique de certaines parties de la formation réticulée. Le comportement de colère du chat décortiqué dépend, de même que la désynchronisation corticale et l'état d'éveil chez les animaux intacts, du tonus réticulaire ascendant. En conclusion, il est fort possible que des mécanismes afférents identiques peuvent agir à la fois sur le comportement de vigilance et sur les activités somatiques et viscérales du comportement émotionnel d'origine diencéphalique.
    Notes: Summary The afferent modulation of the central nervous mechanisms regulating conscious behaviour is discussed, and compared to the effects of afferent and brain stem stimulation on the emotional behaviour of diencephalic origin. The electroencephalographic synchronization and sleep induced by stimulating the carotid sinus baroceptors in encéphale isolé or intact animals is paralleled by the inhibition of the spontaneous sham rage outbursts of the decorticate cat by natural baroceptive stimulation; on the other hand, the carotid body chemoceptors do not only exert an arousing action, but are also capable of precipitating sham rage fits in the decorticate cat. As in encéphale isolé or intact animals suitably timed reticular stimuli may induce either desynchronization and arousal, or synchronization and sleep, likewise rage fits may either be evoked or inhibited by electrical stimulation within the reticular formation. Finally, the rage behaviour of the decorticate cat depends, like cortical desynchronization and wakefulness in intact animals, upon a tonic background of ascending reticular activity. It is suggested that identical, or closely related, mechanisms may affect both conscious alert behaviour and several somatic and visceral activities, such as those subserving emotional behaviour.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 25 (1969), S. 152-153 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Résumé La décharge de fibres sympathiques préganglionnaires isolées, faisant probablement partie de l'innervation efférente du cœur, a été étudiée sur des chats, soit anésthésiés, soit décérébrés, soit spinalisés, par rapport à l'occlusion d'un segment de l'artère coronaire de gauche.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 22 (1966), S. 315-316 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Riassunto La stimolazione elettrica ad alta cadenza (100–600 c/sec) del puro contingente di fibre muscolari appartenenti al gruppo I è in grado di scatenare accessi di falsa rabbia nel gatto decorticato, anche dopo ablazione del cervelletto e somministrazione di curarizzanti.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Biological cybernetics 81 (1999), S. 119-129 
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract. A method that enables measurement of the degree of coupling between two signals is presented. The method is based on the definition of an uncoupling function calculating, by means of entropy rates, the minimum amount of independent information (i.e. the information carried by one signal which cannot be derived from the other). An estimator of the uncoupling function able to deal with short segments of data (a few hundred samples) is proposed, thus enabling the method to be used for usual experimental recordings. A synchronisation index is derived from the estimate of the uncoupling function by means of a minimisation procedure. It quantifies the maximum amount of information exchanged between the two signals. Simulations in which non-linear coordination schemes are produced and changes in the coupling strength are artificially induced are used to check the ability of the proposed index to measure the degree of synchronisation between signals. The synchronisation analysis is utilised to measure the coupling strength between the beat-to-beat variability of the sympathetic discharge and ventilation in decerebrate artificially ventilated cats and the degree of synchronisation between the beat-to-beat variability of the heart period and ventricular repolarisation interval in normal subjects and myocardial infarction patients. The sympathetic discharge and ventilation are strongly coupled and the coupling strength is not affected by manoeuvres capable of increasing or depressing sympathetic activity. The synchronisation is lost after spinalisation. The synchronisation analysis confirms that the heart period and ventricular repolarisation interval are well coordinated. In normal subjects, the synchronisation index is not modified by experimental conditions inducing changes in the sympathovagal balance. On the contrary, it strongly decreases after myocardial infarction, thus detecting and measuring the uncoupling between the heart period and ventricular repolarisation interval.
    Type of Medium: Electronic Resource
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