Records |
Author |
Spadavecchia, C.; Arendt-Nielsen, L.; Andersen, O.K.; Spadavecchia, L.; Doherr, M.; Schatzmann, U. |
Title |
Comparison of nociceptive withdrawal reflexes and recruitment curves between the forelimbs and hind limbs in conscious horses |
Type |
Journal Article |
Year |
2003 |
Publication |
American journal of veterinary research |
Abbreviated Journal |
Am J Vet Res |
Volume |
64 |
Issue |
6 |
Pages |
700-707 |
Keywords |
Animals; Consciousness; Female; Forelimb/*physiology; Hindlimb/*physiology; Horses/*physiology; Male; Nociceptors/physiology; Pain/*physiopathology/*veterinary; Pain Threshold/physiology; Recruitment, Neurophysiological/physiology; Reflex/*physiology |
Abstract |
OBJECTIVE: To compare nociceptive withdrawal reflexes (NWRs) evoked from the distal aspect of the left forelimb and hind limb in conscious standing horses and to investigate NWR recruitment for graded electrical stimulation intensities. ANIMALS: 20 adult horses. PROCEDURE: Surface electromyographic (EMG) activity evoked by transcutaneous electrical stimulation of the digital palmar (or plantar) nerve was recorded from the common digital extensor and cranial tibial muscles. Stimuli consisted of 25-millisecond train-of-5 constant current pulses. Current intensity was gradually increased until NWR threshold intensity was reached. The EMG signal was analyzed for quantification of the NWR. Behavioral responses accompanying the reflex were scored (scale, 0 to 5). The NWR recruitment curves were determined at 0.9, 1.1, 1.2, and 1.3 times the NWR threshold intensity. RESULTS: The NWR threshold was significantly higher for the hind limb (median value, 6.6 mA; range, 3 to 10 mA) than the forelimb (median, 3 mA; range, 1.7 to 5.5 mA). The NWR of the hind limb had a significantly longer latency (median, 122.8 milliseconds; range, 106 to 172 milliseconds), compared with the forelimb (median, 98 milliseconds; range, 86 to 137 milliseconds), and it was associated with significantly stronger behavioral reactions. Gradual increase of NWR amplitude was evident at increasing stimulation intensities and supported by the behavioral observations. CONCLUSIONS AND CLINICAL RELEVANCE: We documented NWRs evoked from the forelimb and hind limb and their recruitment with stimuli of increasing intensity in horses. These results provide a basis for use of NWRs in studies on nociceptive modulation in horses. |
Address |
Department of Clinical Veterinary Sciences, University of Berne, Switzerland |
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English |
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ISSN |
0002-9645 |
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Notes |
PMID:12828255 |
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no |
Call Number |
refbase @ user @ |
Serial |
93 |
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Author |
Williams, D.O.; Boatwright, R.B.; Rugh, K.S.; Garner, H.E.; Griggs, D.M.J. |
Title |
Myocardial blood flow, metabolism, and function with repeated brief coronary occlusions in conscious ponies |
Type |
Journal Article |
Year |
1991 |
Publication |
The American journal of physiology |
Abbreviated Journal |
Am J Physiol |
Volume |
260 |
Issue |
1 Pt 2 |
Pages |
H100-9 |
Keywords |
Animals; Consciousness/*physiology; Coronary Circulation/*physiology; Coronary Disease/pathology/*physiopathology; Disease Models, Animal; Hemodynamic Processes/physiology; Horses/*physiology; Hydrogen/metabolism; Lactates/metabolism; Myocardium/*metabolism/pathology; Norepinephrine/metabolism; Potassium/metabolism; Regional Blood Flow |
Abstract |
Studies were performed in the conscious pony instrumented with a Doppler flow probe and hydraulic occluder on the left anterior descending coronary artery (LAD), sonomicrometry crystals and intraventricular micromanometer in the left ventricle, and catheters in the left atrium and anterior interventricular vein. Two-minute LAD occlusions were performed every 30 min continuously or during working hours. Data on release of catabolites (potassium, hydrogen ions, and lactate) and norepinephrine from the initially dysfunctional region were obtained periodically during a regimen of 445 +/- 56 occlusions in six animals. Regional myocardial blood flow was measured (microsphere method) before and after an occlusion regimen in four animals. Marked release of catabolites and norepinephrine from the initially dysfunctional region was noted in association with early occlusions when myocardial segment function was severely reduced. With further occlusions, release of these substances decreased while segment function improved. Blood flow was markedly decreased in the initially dysfunctional region during an early occlusion but was at the control level during a later occlusion. Although the metabolic findings are consistent with protection due to “ischemic preconditioning” and no increase in collateral perfusion, the inverse relationship noted between catabolite release and segment function is best explained by flow-dependent mechanisms. These results, together with the myocardial blood flow data, serve to validate a previous assumption that protection against regional myocardial dysfunction under these conditions is due to increased collateral perfusion. |
Address |
Department of Physiology, University of Missouri, Columbia 65212 |
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English |
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ISSN |
0002-9513 |
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PMID:1992786 |
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refbase @ user @ |
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98 |
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Author |
Marinsek, N.L.; Gazzaniga, M.S.; Miller, M.B. |
Title |
Chapter 17 – Split-Brain, Split-Mind |
Type |
Book Chapter |
Year |
2016 |
Publication |
The Neurology of Conciousness (Second Edition) |
Abbreviated Journal |
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Volume |
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Issue |
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Pages |
271-279 |
Keywords |
Split-brain; consciousness; lateralization; modular; left hemisphere interpreter |
Abstract |
The corpus callosum anatomically and functionally connects the two cerebral hemispheres. Despite its important role in interhemispheric communication however, severing the corpus callosum produces few--if any--noticeable cognitive or behavioral abnormalities. Incredibly, split-brain patients do not report any drastic changes in their conscious experience even though nearly all interhemispheric communication ceases after surgery. Extensive research has shown that both hemispheres remain conscious following disconnection and the conscious experience of each hemisphere is private and independent of the other. Additionally, the conscious experiences of the hemispheres appear to be qualitatively different, such that the consciousness of the left hemisphere is more enriched than the right. In this chapter, we offer explanations as to why split-brain patients feel unified despite possessing dual conscious experiences and discuss how the divided consciousness of split-brain patients can inform current theories of consciousness. |
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Academic Press |
Place of Publication |
San Diego |
Editor |
Laureys, S.; Gosseries, O.; Tononi, G. |
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978-0-12-800948-2 |
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Call Number |
Equine Behaviour @ team @ |
Serial |
6648 |
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