Laboratory of Molecular Physiology
Stephen Ikeda
Education
1976–1983: Univ. of Maryland School of Medicine, Baltimore, Maryland. Dept. of Pharmacology and Experimental Therapeutics. Degree: Ph.D. in Pharmacology under the direction of Dr. Edson X. Albuquerque. Thesis title: Interactions of bupivacaine with ionic channels of nicotinic receptors. Graduated with distinction.
1976–1980: Univ. of Maryland School of Medicine, Baltimore, Maryland. Degree: M.D. Graduated cum laude.
1972–1976: George Washington University, Washington, D.C. Degree: B.Sc. in Chemistry/Zoology (double major). Graduated with honors.
Research Interests
The main focus of my laboratory is to understand signal transduction pathways underlying ion channel modulation in neurons. In recent years, we have concentrated on understanding the molecular mechanisms involved with neurotransmitter-mediated modulation of N-type (Cav2.2) Ca2+ channels in sympathetic neurons. As Ca2+ flux through the N- and closely related P/Q-type (Cav2.1) Ca2+ channels triggers exocytotic release from presynaptic nerve terminals, modulation of neuronal Ca2+ channels represents an important mechanism for fine tuning synaptic transmission at both peripheral and central synapses. A few years ago, we discovered that a well-described mode of N-type Ca2+ channel modulation, termed voltage-dependent inhibition, was mediated by G protein bg subunits (Gbg). Work from out laboratory and others define a compact signaling pathway defined comprised of G protein coupling receptor (GPCR), G protein heterotrimer, and the a1 subunit of the Ca2+ channel. Within this framework, several avenues of inquiry will be pursued using a combination of electrophysiological, molecular biological, biochemical, and optical techniques.
Selected Publications
Ward Y, Spinelli B, Quon MJ, Chen H, Ikeda SR, Kelly K. Phosphorylation of Critical Serine Residues in Gem Separates Cytoskeletal Reorganization from Down-Regulation of Calcium Channel Activity. Mol Cell Biol. 2004 Jan 15;24(2):651-661. 
Ruiz-Velasco V, Ikeda SR. A splice variant of the G protein beta 3-subunit implicated in disease states does not modulate ion channels. Physiol Genomics. 2003 Apr 16;13(2):85-95. Epub 2003 Feb 20.
Kammermeier PJ, Davis MI, Ikeda SR. Specificity of metabotropic glutamate receptor 2 coupling to G proteins.Mol Pharmacol. 2003 Jan;63(1):183-91.
Kammermeier PJ, Ikeda SR. Metabotropic glutamate receptor expression in the rat superior cervical ganglion.Neurosci Lett. 2002 Sep 27;330(3):260-4.
Ikeda SR, Kammermeier PJ. M current mystery messenger revealed? Neuron. 2002 Aug 1;35(3):411-2. Review.
Grunewald S, Schupp BJ, Ikeda SR, Kuner R, Steigerwald F, Kornau HC, Kohr G. Importance of the gamma-aminobutyric acid(B) receptor C-termini for G-protein coupling. Mol Pharmacol. 2002 May;61(5):1070-80.
Kammermeier PJ, Ikeda SR. Desensitization of group I metabotropic glutamate receptors in rat sympathetic neurons. J Neurophysiol. 2002 Apr;87(4):1669-76.
Ruiz-Velasco V, Ikeda SR, Puhl HL. Cloning, tissue distribution, and functional expression of the human G protein beta 4-subunit. Physiol Genomics. 2002 Feb 11;8(1):41-50. Epub 2001 Nov 20.
Ruiz-Velasco V, Ikeda SR. Functional expression and FRET analysis of green fluorescent proteins fused to G-protein subunits in rat sympathetic neurons. J Physiol. 2001 Dec 15;537(Pt 3):679-92.
Kammermeier PJ, Ikeda SR. A role for Seven in Absentia Homolog (Siah1a) in metabotropic glutamate receptor signaling. BMC Neurosci. 2001;2(1):15. Epub 2001 Oct 08.
Park KS, Jeong SW, Cha SK, Lee BS, Kong ID, Ikeda SR, Lee JW. Modulation of N-type Ca2+ currents by A1-adenosine receptor activation in male rat pelvic ganglion neurons. J Pharmacol Exp Ther. 2001 Nov;299(2):501-8.
Ikeda SR. Related Articles, Links
Signal transduction. Calcium channels--link locally, act globally. Science. 2001 Oct 12;294(5541):318-9. No abstract available.
Mailing Address
Chief, Lab. of Molecular Physiology
NIH/NIAAA/DICBR/LMP
Park Building Room 150
12420 Parklawn Dr., MSC 8115
Bethesda, Maryland 20892-8115 (regular mail)
Rockville, Maryland 20852 (express mail)