Graduate Studies Faculty

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Steven W. Johnson, M.D., Ph.D.

Professor of Neurology
Admin Unit: SOM-Neurology Department
Phone: 503 220 3416
Lab Phone: 503 220 8262 x-56576
Fax: 503 721 7906
Office: Portland VA Medical Center, building 101, room 416
Mail Code: PVAMC RD-61
Neuroscience Graduate Program
Research Interests:
Neuropharmacology Neurophysiology Parkinson's disease dopamine basal ganglia; medical, Neurobiology of Disease » PubMed Listing
Preceptor Rotations
Dr. Johnson has not indicated availability for preceptor rotations at this time.
Faculty Mentorship
Dr. Johnson has not indicated availability as a mentor at this time.

Summary of Current Research
I wear two "hats" at the University, one as a neuropharmacologist and the other as a clinical neurologist. My clinical interests focus on movement disorders, including Parkinson's disease, Huntington's disease, Tourette syndrome, and tardive dyskinesia. The neurotransmitter dopamine is pivotal in the pathophysiology of these disorders. My lab primarily uses electrophysiological techniques to study the physiology and pharmacology of dopamine-related synaptic transmission of the rat basal ganglia. Current research projects in the lab include: 1) the effects of excitatory amino acids on the pattern of action potential generation in basal ganglia neurons recorded in vitro in the rat midbrain slice, 2) presynaptic regulation of excitatory and inhibitory postsynaptic potentials in basal ganglia neurons, and 3) factors that lead to neurotoxicity of midbrain dopamine neurons in animal models of Parkinson's disease. It is hoped that the basic research performed in our laboratory will improve our understanding of basal ganglia physiology and facilitate the treatment of both hypo- and hyperkintetic movement disorders.

Recent Publications

Shen K-Z and Johnson SW (2013) Group I mGluRs evoke K-ATP current by intracellular Ca2+ mobilization in rat subthalamus neurons. J Pharmacol Exp Therap 345:139-150. PMCID: pending

Shen K-Z and Johnson SW (2012) Chronic dopamine depletion augments the functional expression of K-ATP channels in the rat subthalamic nucleus. Neurosci Lett 531:104-108. PMCID: PMC3513517

Munhall AC, Wu Y-N, Belknap JK, Meshul CK, and Johnson SW (2012) NMDA alters rotenone toxicity in rat substantia nigra zona compacta and ventral tegmental area dopamine neurons. Neurotoxicol 33:429-435.

Shen K-Z and Johnson SW (2012) Regulation of polysynaptic subthalamonigral transmission by D2, D3 and D4 dopamine receptors in rat brain slices. J Physiol (Lond) 590:2273-2284.

Shen K-Z and Johnson SW (2012) Gamma-aminobutyric acid-B receptor activation suppresses stimulus-evoked burst firing in rat substantia nigra reticulata neurons. NeuroReport 23:40-44.

Wu Y-N and Johnson SW (2011) Dopamine oxidation facilitates rotenone-dependent potentiation of NMDA currents in rat substantia nigra dopamine neurons. Neurosci 195:138-144.

Wu Y-N, Munhall AC, and Johnson SW (2011) Mitochondrial uncoupling agents antagonize rotenone actions in rat substantia nigra dopamine neurons. Brain Res 1395:86-93.

Shen K-Z and Johnson SW (2010) Ca2+ influx through NMDA-gated channels activates ATP-sensitive K+ currents through a nitric oxide-cGMP pathway in subthalamic neurons. J Neurosci 30:1882-1893.

Wu Y-N and Johnson SW (2009) Rotenone reduces Mg2+-dependent block of NMDA currents in substantia nigra dopamine neurons. Neurotoxicol 30:320-325.

Ph.D., Oregon Health & Science University, 1981
M.D., University of Colorado Health Sciences University, 1985

Non-Academic Interests
I play keyboards in a rock band