Faculty Profiles

 

Current Research: 

Ralph Lydic, PhD., is the Bert La Du Professor of Anesthesiology, Professor of Physiology, and Associate Chair Anesthesia Research. The National Heart, Lung, and Blood Institute of the National Institutes of Health funds Dr. Lydic's laboratory. The goals of his research programs are to elucidate the mechanisms by which sleep, opioids, and volatile anesthetics depress breathing and arousal. The evolutionary perspective, and current data, supports the view that neurons generating sleep and wakefulness preferentially modulate the ability of opioids, hypnotics, and anesthetics to obtund wakefulness. This concept underlies work in Dr. Lydic's laboratory characterizing the neurochemical and signal transduction processes through which cholinergic neurons modulate sleep, arousal, and autonomic control. Recent work has shown that adenosine and nitric oxide modulate pontine acetylcholine release and arousal. A second research program is characterizing the effects of opioids on cholinergic neurotransmission. These studies aim to understand the cellular and molecular mechanisms by which opioids inhibit cholinergic neurotransmission and disrupt sleep and breathing. Both of these research programs encourage an active interaction between basic and clinical investigators.

 

Representative Publications:

Douglas CL, Bowman, GN, Baghdoyan HA, and Lydic R. "C57BL/6J and B6.V-LEPOB Mice Differ in the Cholinergic Modulation of Sleep and Breathing." J App Physiol, 98:918-929, 2005.

Lydic R. "Performance-Enhancing Drugs Present a Double-Edge Sword." APSF Newsletter, pg 5, Spring 2005 .

 

Lydic R and Baghdoyan HA. "Sleep, Anesthesiology, and the Neurobiology of Arousal State Control." Anesthesiolog, 103: 1268-95, 2005.

Osman NI, Baghdoyan HA, Lydic R. "Morphine Inhibits Acetylcholine Release in Rat Prefrontal Cortex when Delivered Systemically or by Microdialysis to Basal Forebrain." Anesthesiology, 103: 779-87, 2005.

 

Lydic R and Baghdoyan HA. "Sleep and Anesthesia." Foundations of Anesthesia: Basic and Clinical Sciences, 2nd Edition. Edited by H.C. Hemmings and P.M. Hopkins. 361-371, 2005.

 

Bernard R, Lydic R, and Baghdoyan HA. "Hypocretin Receptor-Activated G Proteins Revealed by [ 35S]GTP g S Autoradiography." The Orexin/Hypocretin System: Physiology and Pathophysiology, editors: S. Nishino and Takeshi Sakurai. 83-96, 2006 .

 

Bernard R, Lydic R, Baghdoyan HA. "Hypocretin (Orexin) Receptor Subtypes Differentially Enhance Acetylcholine
Release and Activate G Protein Subtypes in Rat Pontine Reticular Formation." J Pharmacol Exp Ther, 317:163-171, 2006.

 

Lydic R and Baghdoyan HA. "Relevance of Anesthesiology for Sleep Medicine." Encyclopedia of Sleep Medicine, edited by T. Lee-Chiong. 927-932, 2006.

 

Lydic R, Garza-Grande R, Struthers R, Baghdoyan HA. "Nitric Oxide in B6 Mouse and Nitric Oxide-Sensitive Soluble Guanylate Cyclase in Cat Modulate Acetylcholine Release in Pontine Reticular Formation." J Appl Physiol, 100:1666-1673, 2006.

Coleman CG, Baghdoyan HA, Lydic R. "Dialysis Delivery of an Adenosine A2A Agonist into the Pontine Reticular Formation of C57BL/6J Mouse Increase Pontine Acetylcholine Release and Sleep." J Neurochem, 96:1750-1759, 2006.

Lydic R. "Sleep Disruption is Related to Allelic Variation in the Ob Gene." Am J Physiol Regul Integr Comp Physiol, 290:R892-893, 2006.

 

Lydic R and HA Baghdoyan. Neurochemical mechanisms mediating opioid-induced REM sleep disruption. In: Sleep and Pain, edited by G. Lavigne, M. Choiniere, B.J. Sessle, and P. Soja. Seattle : International Association for the Study of Pain, pp 99-122, 2007

 

Hambrecht VS, Vilsides PE, Row BW, Gozal D, Baghdoyan HA, Lydic R, Hypocia modulated cholinergic but not opiod activation of G proteins in rat hippocampus. Hippocampus, 2007; 17(10):934-42

 

Watson CJ, Lydic R, Baghdoyan HA. "Sleep and GABA Levels in the Oral Part of Rat Pontine Reticular Formation are Decreased by Local and Systemic Administration of Morphine." Neuroscience, 144:375-86, 2007.

 

Skulsky EM, Osman NI, Baghdoyan HA, Lydic R, Microdialysis delivery of morphine to the hypoglossal nucleus of Wistar rat increases hypoglosssal acetylcholine release. Sleep. 2007 May 1; 30(5);566-73

 

Lydic R, and H.A. Baghdoyan. Acetylcholine modulates sleep and wakefulness: A synaptic perspective. In: The Neurochemistry of Sleep and Wakefulness. Edited by J.M. Monti, S.R. Pandi-Perumal, and C.M. Sinton. Cambridge University Press, (in press) 2008

 

Skulsky EM, Osman NI, Baghdoyan HA, Lydic R.  Microdialysis delivery of morphine to the hypoglossal nucleus of Wistar rat increases hypoglossal acetylcholine release.  Sleep 30:566-573, 2007.

 

Hambrecht VS, Vlisides PE, Row BW, Gozal D, Baghdoyan HA, and Lydic R.  Cholinergic and opioid activation of G proteins in rat hippocampus: Modulation by hypoxia.  Hippocampus 17: 934-942, 2007.

 

Watson CJ, Soto-Calderon H, Lydic R and Baghdoyan  HA. Wakefulness is increased by increasing GABA Levels in rat pontine reticular formation:  A possible mechanism by which hypocretin-1 promotes arousal. Sleep 31: 453- 464, 2008.

 

Brummett CM, Norat MA, Palmisano JM, Lydic, R.  Perineural administration of dexmedetomidine in combination with bupivacaine enhances sensory and motor blockade in sciatic nerve block in rat.  Anesthesiology (In Press) 2008.

 

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