Martin F. Schneider, PhD

• Yale University, BS Biochemistry (honors; magna cum laude) 

• Tufts University School of Medicine, completed 2 years of Medical School

• University College, London, UK, 1 year as a special student in Biophysics and Physiology

• Duke University, PhD in Physiology

• Yale University School of Medicine, postdoctoral training in Physiology

Dr Schneider is an internationally known leader in skeletal muscle excitation-contraction coupling, the series of steps whereby electrical depolarization of the normally inside negative muscle membrane potential initiates release  of calcium ions (Ca2+) from their intracellular storage location, the muscle sarcoplasmic reticulum (SR), allowing Ca2+ ions bind to regulatory sites on muscle contractile filaments, which serves as a switch to permit contractile filament interaction, producing force development and muscle shortening.  In pioneering work in collaboration with his post doc mentor Dr W.K. Chandler (Yale University), Dr Schneider made the first measurements of tiny electrical currents (charge displacement currents or channel “gating” currents) due to the redistribution of charged voltage sensor proteins within the muscle membrane.  Such gating currents were previously predicted in the classic studies of Hodgkin and Huxley on voltage dependent channel activation underlying the action potential in nerve axons, and were first detected in any excitable cell membrane by Schneider and Chandler in skeletal muscle, where they control Ca2+ release from Ca2+ release channels in the spatially immediately adjacent SR membrane.  Analogous gating currents were subsequently identified by other groups for gating voltage dependent Na+, K+ and Ca2+ channels in other excitable cells. 

As an Assistant Professor and Associate Professor (tenured) in the Department of Physiology at the University of Rochester School of Medicine, Dr Schneider examined the functional role of muscle intramembrane charge movement in the regulation of Ca2+ release from the SR in skeletal muscle fibers, developing single and double gap techniques for doing voltage clamp studies on muscle fibers with maintained or suppressed contraction, respectively. He also developed procedures for using dyes which changed absorbance on Ca2+ binding to monitor Ca2+ release from intracellular stores (sarcoplasmic reticulum) in response to membrane depolarization and the ensuing membrane charge movement.  Dr Schneider also spent a year's sabbatical from the University of Rochester at the Neurobiology Laboratory, Ecole Normale Superieure, Paris, France, where he studied Na+ channel gating current, and its modification by several neuro toxins.

After moving to UMSOM, Dr Schneider investigated modulation of the coupling of voltage sensor charge displacement to the SR Ca2+ release channel activation in the process of excitation contraction coupling, including advanced imaging techniques with fluorescent Ca2+ indicators to characterize both global cytoplasmic Ca2+ signals during depolarization, as well as local Ca2+ release events, known as Ca2+ sparks. These local intracellular events were discovered and characterized in cardiac muscle cells by Dr Lederer at UM SOM, who collaborated with Dr Schneider in the initial studies on Ca2+ sparks in skeletal muscle. In addition, more recent work in the Schneider lab utilizes confocal fluorescence imaging to study nucleo-cytoplasmic movements of several transcriptional regulator molecules (NFAT, HDACs, Foxo) in skeletal muscle fibers.  In addition, Dr Schneider is the founding and current director and PI of the NIH/NIAMS-funded Interdisciplinary Training Program in Muscle Biology (now in year 21 of continuous funding), which provides support annually for 5 pre doc and 5 post doc trainees studying various aspects of skeletal, cardiac or smooth muscle biology and disease at UMSOM.  

Dr Schneider’s research contributions have been recognized by an NIH/NINDS Career Development Award, an NIH/NINDS Javits Neuroscience Investigator Award, an NIH/NIAMS MERIT Award (ongoing), chairmanship of a Gordon Research Conference on Muscle: Excitation-Contraction Coupling and an honorary degree from the University of Debrecen, Debrecen, Hungary.  His current NIH research grant has been continuously funded for 32 years.    

Skeletal muscle, calcium signaling, muscle cell signaling, excitation-contraction coupling, membrane voltage sensors, gating currents, Ca2+ channels, excitability, neuronal signaling, nucleo-cytoplasmic signaling, NFAT, HDAC, Foxo, cell membrane biophysics, cell electrical properties, muscle plasticity, muscle fiber type, muscle growth, muscular dystrophy, hypokalemic periodic paralysis, muscle membranes, muscle sarcoplasmic reticulum Ca2+ release, cytoplasmic Ca2+ transients, local Ca2+ signals, Ca2+ sparks, S100A1, calmodulin, calmodulation.

S100A1 and calmodulin regulation of ryanodine receptor in striated muscle.

Prosser BL, Hernández-Ochoa EO, Schneider MF.

Cell calcium. 2011; 50(4):323-31. NIHMSID: NIHMS315208 PMID:21784520; PMCID:PMC3185186

Voltage clamp methods for the study of membrane currents and SR Ca(2+) release in adult skeletal muscle fibres.

Hernández-Ochoa EO, Schneider MF.

Progress in biophysics and molecular biology. 2012; 108(3):98-118. NIHMSID: NIHMS35243;  PMID:22306655;

PMCID:PMC3321118

Kinetics of nuclear-cytoplasmic translocation of Foxo1 and Foxo3A in adult skeletal muscle fibers.

Schachter TN, Shen T, Liu Y, Schneider MF.

American journal of physiology. Cell physiology. 2012; 303(9):C977-90.  PMID:22932683; PMCID:PMC3492827

β1a490-508, a 19-residue peptide from C-terminal tail of Cav1.1 β1a subunit, potentiates voltage-dependent calcium release in adult skeletal muscle fibers.

Hernández-Ochoa EO, Olojo RO, Rebbeck RT, Dulhunty AF, Schneider MF.

Biophysical journal. 2014; 106(3):535-47. PMID:24507594; PMCID:PMC3944469

Alternating bipolar field stimulation identifies muscle fibers with defective excitability but maintained local Ca(2+) signals and contraction.

Hernández-Ochoa EO, Vanegas C, Iyer SR, Lovering RM, Schneider MF.

Skelet Muscle. 2016 Feb 5;6:6. doi: 10.1186/s13395-016-0076-8. eCollection 2016. PMID: 26855765