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Richard O Davies, DVM, PhD
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Contact information
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University of Pennsylvania
25 School of Veterinary Medicine
27 Clinical Studies - Philadelphia
11 Room 2011
37 3900 Delancey Street
Philadelphia, PA 19104
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25 School of Veterinary Medicine
27 Clinical Studies - Philadelphia
11 Room 2011
37 3900 Delancey Street
Philadelphia, PA 19104
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Office: 215-898-1531
32 Fax: 215-573-8183
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Email:
rodavies@vet.upenn.edu
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rodavies@vet.upenn.edu
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Education:
21 8 DVM 20 (Veterinary Medicine) c
2b Cornell University, 1960.
21 8 PhD 17 (Physiology) c
33 University of Pennsylvania, 1964.
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Permanent link21 8 DVM 20 (Veterinary Medicine) c
2b Cornell University, 1960.
21 8 PhD 17 (Physiology) c
33 University of Pennsylvania, 1964.
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Description of Research Expertise
463 Current research involves studies of the neural mechanisms involved in the control of brainstem motoneurons that innervate upper airway muscles, particularly in reference to the control of the upper airway during rapid eye movement (REM) sleep and sleep-disordered breathing. For this, we use a urethane-anesthetized rat model in which REM sleep-like episodes are elicited by microinjections of carbachol (a cholinergic agonist) into a distinct site in the dorsal pontine tegmentum. These episodes can be triggered repeatedly and comprise events typical of REM sleep, such as cortical activation, hippocampal theta rhythm, silencing of pontine adrenergic neurons, slowing of the respiratory rate, and suppression of postural and upper airway motoneuronal activity. The role of the adrenergic (noradrenaline and serotonin) systems of the brainstem in the control of upper airway motoneurons (hypoglossal, pharyngeal, laryngeal), and its relation to REM sleep atonia, is currently being investigated using a variety of complementary neurophysiological, neuropharmacological and neuroanatomical techniques.e 29
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114 Fenik, V., H. Ogawa, R.O. Davies and L. Kubin. : Carbachol injections into the ventral pontine reticular formation activate locus coeruleus cells in urethane-anesthetized rats. Sleep 28: 560-570, 2005.
133 Fenik, V.B., M. Malinowska, R.O. Davies and L. Kubin. : Medullary control of the upper airway during REM sleep. Clinical and Neurophysiological Aspects of Sleep. V.M. Kumar & H.N. Mallick (eds.). Bologna: Medimond, Page: 47-53, 2005.
145 Fenik, V.B., R.O. Davies and L. Kubin: Noradrenergic, serotonergic and GABAergic antagonists injected together into the XII nucleus abolish the REM sleep-like depression of hypoglossal motoneuronal activity. Journal of Sleep Research 14: 419-429, 2005.
13a Fenik, V., R.O. Davies and L. Kubin. : Combined antagonism of aminergic and amino acid inhibitory receptors in the XII nucleus abolishes REM sleep-like depression of hypoglossal motoneuronal activity. Arch. Ital. Biol., 142: 237-249, 2004.
1b2 Volgin, D.V.,V.B. Fenik, R. Fay, S. Okabe, R.O. Davies and L. Kubin: Serotonergic receptors and effects in hypoglossal and laryngeal motoneurons. Post-Genomic Perspectives in Modeling and Control of Breathing. J. Champagnat, M. Denavit-Saubié, G. Fortin, A.S. Foutz and M. Thoby-Brisson. (eds.). Amsterdam: Kluwer Academic/Plenum, Page: 183-188, 2004.
fd Kubin, L. and R.O. Davies. : Mechanisms of airway hypotonia Pathogenesis, Diagnosis and Treatment of Sleep Apnea. A.I. Pack (eds.). New York: Marcel Dekker, Page: 99-154, 2002.
c6 Fenik, V. B., V. Marchenko, P. Janssen, R.O. Davies and L. Kubin: A5 cells are silenced when REM sleep-like signs are elicited by pontine carbachol 4b Journal of Applied Physiology 93: 1448-1456, 2002.
128 Woch, G., H. Ogawa, R.O. Davies and L. Kubin. : Behavior of hypoglossal inspiratory premotor neurons during the carbachol-induced, REM sleep-like suppression of upper airway motoneurons. Brain Research 130: 508-520, 2000.
118 Fenik, V., R.O. Davies, A.I. Pack and L. Kubin: Differential suppression of upper airway motor activity during carbachol-induced, REM sleep-like atonia. American Journal of Physiology 275: R1013-R1024, 1998.
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Selected Publications
134 Fenik, V.B., R.O. Davies and L. Kubin. : REM sleep-like atonia of hypoglossal (XII) motoneurons is caused by loss of noradrenergic and serotonergic inputs. American Journal of Respiratory Critical Care Medicine 172: 1322-1330, 2005.114 Fenik, V., H. Ogawa, R.O. Davies and L. Kubin. : Carbachol injections into the ventral pontine reticular formation activate locus coeruleus cells in urethane-anesthetized rats. Sleep 28: 560-570, 2005.
133 Fenik, V.B., M. Malinowska, R.O. Davies and L. Kubin. : Medullary control of the upper airway during REM sleep. Clinical and Neurophysiological Aspects of Sleep. V.M. Kumar & H.N. Mallick (eds.). Bologna: Medimond, Page: 47-53, 2005.
145 Fenik, V.B., R.O. Davies and L. Kubin: Noradrenergic, serotonergic and GABAergic antagonists injected together into the XII nucleus abolish the REM sleep-like depression of hypoglossal motoneuronal activity. Journal of Sleep Research 14: 419-429, 2005.
13a Fenik, V., R.O. Davies and L. Kubin. : Combined antagonism of aminergic and amino acid inhibitory receptors in the XII nucleus abolishes REM sleep-like depression of hypoglossal motoneuronal activity. Arch. Ital. Biol., 142: 237-249, 2004.
1b2 Volgin, D.V.,V.B. Fenik, R. Fay, S. Okabe, R.O. Davies and L. Kubin: Serotonergic receptors and effects in hypoglossal and laryngeal motoneurons. Post-Genomic Perspectives in Modeling and Control of Breathing. J. Champagnat, M. Denavit-Saubié, G. Fortin, A.S. Foutz and M. Thoby-Brisson. (eds.). Amsterdam: Kluwer Academic/Plenum, Page: 183-188, 2004.
fd Kubin, L. and R.O. Davies. : Mechanisms of airway hypotonia Pathogenesis, Diagnosis and Treatment of Sleep Apnea. A.I. Pack (eds.). New York: Marcel Dekker, Page: 99-154, 2002.
c6 Fenik, V. B., V. Marchenko, P. Janssen, R.O. Davies and L. Kubin: A5 cells are silenced when REM sleep-like signs are elicited by pontine carbachol 4b Journal of Applied Physiology 93: 1448-1456, 2002.
128 Woch, G., H. Ogawa, R.O. Davies and L. Kubin. : Behavior of hypoglossal inspiratory premotor neurons during the carbachol-induced, REM sleep-like suppression of upper airway motoneurons. Brain Research 130: 508-520, 2000.
118 Fenik, V., R.O. Davies, A.I. Pack and L. Kubin: Differential suppression of upper airway motor activity during carbachol-induced, REM sleep-like atonia. American Journal of Physiology 275: R1013-R1024, 1998.
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