Photo of John T. Williams, Ph.D.

John T. Williams Ph.D.

After earning his Ph.D. in Pharmacology from Loyola University in 1979, John Williams worked as a research scientist at the Max-Planck Institute in Munich and at Loyola University School of Medicine. He then spent five years as a research scientist in Biological Sciences at the Massachusetts Institute of Technology. In 1987, he became an assistant scientist at the Vollum Institute and rose to the position of senior scientist in 1996. He holds a concurrent appointment in the Department of Physiology and Pharmacology in the School of Medicine.

Williams and colleagues investigate the early events that lead to the development of tolerance to opioids. Opioids such as morphine are important therapeutic compounds used for the management of pain, but the primary problem with their use is the development of tolerance, where higher doses are required to achieve the same effect. By focusing on the long-term effects of morphine and cocaine on synaptic transmission in the reward centers of the brain—dopamine cells of the ventral tegmental area and GABA cells of the nucleus accumbens—the lab hopes to identify the cellular basis for drug addiction.

Areas of interest

  • opiate desensitization and tolerance
  • receptor trafficking
  • dendrodendritic transmission


  • B.S., St. Lawrence University, Canton New York 1972
  • M.A., State University of New York, Potsdam, Potsdam New York 1975
  • Ph.D., Loyola University, Chicago Illinois 1979


  • "Inositol 1,4,5-triphosphate-evoked responses in midbrain dopamine neurons." Journal of Neuroscience  2000
  • "Developmental changes that regulate the activity of locus coeruleus neurons" Tokai Journal of Experimental and Clinical Medicine June 1999
  • "Transient homologous μ-opioid receptor desensitization in rat locus coeruleus neurons" Journal of Neuroscience  1991
  • "The action of substance P on neurons of the myenteric plexus of the guinea-pig small intestine" Philosophical Transactions of the Royal Society B: Biological Sciences  1979
  • "Dopamine controls the firing pattern of dopamine neurons via a network feedback mechanism" Proceedings of the National Academy of Sciences of the United States of America March 4 2003
  • "Efficacy and kinetics of opioid action on acutely dissociated neurons" Molecular Pharmacology July 1997
  • "Cocaine Decreases Metabotropic Glutamate Receptor mGluR1 Currents in Dopamine Neurons by Activating mGluR5" Neuropsychopharmacology April 1 2015
  • "Cholinergic inhibition of ventral midbrain dopamine neurons" Journal of Neuroscience October 15 2000
  • "Inhibition of firing of myenteric neurones by somatostatin" Brain Research October 20 1978
  • "Noradrenergic inhibition of midbrain dopamine neurons" Journal of Neuroscience May 12 2004
  • "Kappa opioid inhibition of somatodendritic dopamine inhibitory postsynaptic currents" Journal of Neurophysiology January 2007
  • "Presynaptic inhibition of GABA(B)-mediated synaptic potentials in the ventral tegmental area during morphine withdrawal" Journal of Neuroscience March 15 1999
  • "Cellular and synaptic adaptations mediating opioid dependence" Physiological Reviews  2001
  • "Noradrenergic modulation of the hyperpolarization-activated cation current (Ih) in dopamine neurons of the ventral tegmental area" Neuroscience October 26 2007
  • "Does PKC activation increase the homologous desensitization of μ opioid receptors?" British Journal of Pharmacology  2015
  • "Endogenous monoamines inhibit glutamate transmission in the spinal trigeminal nucleus of the guinea-pig" Journal of Physiology February 15 1996
  • "Opioid Receptors and the Regulation of Ion Conductances" Reviews in the Neurosciences  1995
  • "Activation of μ-opioid receptors and block of K IR3 potassium channels and NMDA receptor conductance by l- and d-methadone in rat locus coeruleus" British Journal of Pharmacology November 2010
  • "Modulation of the hyperpolarization-activated current (Ih) by cyclic nucleotides in guinea-pig primary afferent neurons" Journal of Physiology April 1 1996
  • "μ-Opioid agonists inhibit spinal trigeminal substantia gelatinosa neurons in guinea pig and rat" Journal of Neuroscience March 1994
  • "Opioid inhibition of Ih via adenylyl cyclase" Neuron  1994
  • "Desensitization of functional μ-opioid receptors increases agonist off-rate" Molecular Pharmacology  2014
  • "Decreased presynaptic sensitivity to adenosine after cocaine withdrawal" Journal of Neuroscience October 1 1998
  • "Desensitization and trafficking of μ-opioid receptors in locus ceruleus neurons" Molecular Pharmacology March 2012
  • "κ-Opioid receptors also increase potassium conductance" Proceedings of the National Academy of Sciences of the United States of America December 1 1993
  • "Pre- and postsynaptic regulation of locus coeruleus neurons after chronic morphine treatment" European Journal of Neuroscience August 2008
  • "Vasoactive intestinal polypeptide excites neurones of the myenteric plexus" Brain Research October 12 1979
  • "Roles of α1- and α2-adrenoceptors in the nucleus raphe magnus in opioid analgesia and opioid abstinence-induced hyperalgesia" Journal of Neuroscience August 27 2003
  • "Separation of μ-opioid receptor desensitization and internalization" Journal of Neuroscience  2006
  • "Cellular mechanisms of opioid tolerance" Molecular Pharmacology  1987

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