PROPERTIES OF MEMBRANE SIGNALING IN SINGLE CELLS

We are interested in cell signaling by ion channels, neurotransmitters and hormones acting through G-protein coupled receptors and intracellular second messengers including calcium. Our overall goal is to define every step and the molecular mechanisms underlying physiologically interesting activation and inhibition in single cells, with emphasis on events that occur in time scales of microseconds to seconds.

The cell membrane, cytoplasm and intracellular organelles form a rapidly interacting signaling network. We study single neurons, endocrine cells, cell lines, and spermatozoa using techniques associated with the patch clamp: voltage clamp, membrane capacitance, amperometry, optical imaging, photometry of fluorescent indicator dyes and fluorescent proteins, FRET, and subcellular translocation (in confocal microscopy). We have analyzed G-protein coupled modulation of neuronal Ca2+ channels, modulation of K+ channels by plasma membrane phosphoinositide lipids, exocytosis and motions of secretory vesicles, dynamics of intra-organellar calcium, and the flagellar and calcium responses of sperm to endogenous activators.