David Bourget (Western Ontario)
David Chalmers (ANU, NYU)
Rafael De Clercq
Jack Alan Reynolds
Learn more about PhilPapers
BACKGROUND: Through their action on the locus coeruleus, ␣ 2-adrenoceptor agonists induce rapidly reversible sedation while partially preserving cognitive brain functions. Our goal in this observational study was to map brain regions whose activity is modified by clonidine infusion so as to better understand its loci of action, especially in relation to sedation. METHODS: Six ASA I–II right-handed volunteers were recruited. Electroencephalogram (EEG) was monitored continuously. After a baseline H215O activation scan, clonidine infusion was started at a rate ranging from 6 to 10 g ⅐ kgϪ1 ⅐ h Ϫ1. A sequence of 11 similar scans was then performed at 8 min intervals. Plasma clonidine concentration was measured. Using statistical parametric mapping, we sought linear correlations between normalized regional cerebral blood flow (rCBF), an indicator of regional brain activity, and plasma clonidine concentration or spindle EEG activity. RESULTS: Clonidine induced clinical sedation and EEG patterns (spindles) comparable to early stage nonrapid eye movement sleep. A significant negative linear correlation between clonidine concentration and rCBF or spindle activity was observed in the thalamus, prefrontal, orbital and parietal association cortex, posterior cingulate cortex, and precuneus. CONCLUSIONS: The EEG patterns and decreases in rCBF of specific brain regions observed during clonidine-induced sedation are similar to those of early stage nonrapid eye movement sleep. Patterns of deactivated brain regions are also comparable to those observed during general anesthesia or vegetative state, reinforcing the hypothesis that alterations in the activity of a common network occur during these modified conscious states.
|Keywords||No keywords specified (fix it)|
No categories specified
(categorize this paper)
Setup an account with your affiliations in order to access resources via your University's proxy server
Configure custom proxy (use this if your affiliation does not provide a proxy)
|Through your library||
References found in this work BETA
No references found.
Citations of this work BETA
No citations found.
Similar books and articles
T. W. Kjaer, M. Nowak, K. W. Kjaer, A. R. Lou & H. C. Lou (2001). Precuneus-Prefrontal Activity During Awareness of Visual Verbal Stimuli. Consciousness and Cognition 10 (3):356-365.
Stephen C. Fowler (2000). Behavioral Tolerance (Contingent Tolerance) Ismediated in Part by Variations in Regional Cerebral Blood Flow. Brain and Mind 1 (1):45-57.
Alexander A. Fingelkurts, Andrew A. Fingelkurts, Sakari Kallio & Antti Revonsuo (2007). HYPNOSIS INDUCES A CHANGED COMPOSITION OF BRAIN OSCILLATIONS IN EEG: A CASE STUDY. Contemporary Hypnosis 24 (1):3-18.
Axel Cleeremans, Learned Material Content and Acquisition Level Modulate Cerebral Reactivation During Posttraining Rapid-Eye-Movements Sleep.
Arnaud Destrebecqz, Philippe Peigneux, Steven Laureys, Christian Degueldre, Guy Del Fiore, Joel Aerts, Andre Luxen, Martial van der Linden, Axel Cleeremans & Pierre Maquet (2003). Cerebral Correlates of Explicit Sequence Learning. Cognitive Brain Research 16 (3):391-398.
Pierre Rainville, Rrrobert K. Hofbauer, M. Catherine Bushnell, Gary H. Duncan & Donald D. Price (2002). Hypnosis Modulates Activity in Brain Structures Involved in the Regulation of Consciousness. Journal of Cognitive Neuroscience 14 (6):887-901.
Dahlia W. Zaidel (1999). Neuronal Connectivity, Regional Differentiation, and Brain Damage in Humans. Philosophical Explorations 22 (5):854-855.
M. T. Alkire, R. J. Haier & J. H. Fallon (2000). Toward a Unified Theory of Narcosis: Brain Imaging Evidence for a Thalamocortical Switch as the Neurophysiologic Basis of Anesthetic-Induced Unconsciousness. Consciousness and Cognition 9 (3):370-386.
Melanie Boly, Marie-Elisabeth E. Faymonville & Philippe Peigneux (2004). Auditory Processing in Severely Brain Injured Patients: Differences Between the Minimally Conscious State and the Persistent Vegetative State. Archives of Neurology 61 (2):233-238.
Alexander A. Fingelkurts, Andrew A. Fingelkurts, Sergio Bagnato, Cristina Boccagni & Giuseppe Galardi (2013). The Value of Spontaneous EEG Oscillations in Distinguishing Patients in Vegetative and Minimally Conscious States. In Eror Basar & et all (eds.), Application of Brain Oscillations in Neuropsychiatric Diseases. Supplements to Clinical Neurophysiology. Elsevier. 81-99.
Claude Gottesmann (2005). Waking Hallucinations Could Correspond to a Mild Form of Dreaming Sleep Stage Hallucinatory Activity. Behavioral and Brain Sciences 28 (6):766-767.
E. R. John, L. S. Prichep, W. Kox, P. Valdes-Sosa, J. Bosch-Bayard, E. Aubert, M. Tom, F. diMichele & L. D. Gugino (2001). Invariant Reversible QEEG Effects of Anesthetics. Consciousness and Cognition 10 (2):165-183.
Sorry, there are not enough data points to plot this chart.
Added to index2010-12-22
Total downloads1 ( #459,101 of 1,101,833 )
Recent downloads (6 months)1 ( #306,516 of 1,101,833 )
How can I increase my downloads?