Research in my laboratory focuses on the molecular and cellular physiology of carrier protein molecules that actively transport chloride ions (Cl-) across the plasma membrane of neurons and epithelial cells. Specifically, we study some members of the cation-coupled-chloride cotransporter gene/protein family SLC12A: the Na+, K+, 2 Cl- cotransporters (NKCC1 and NKCC2) and the K+-Cl- cotransporters (KCC1, 2, 3 and 4). These carrier proteins play key roles in: intracellular Cl- homeostasis in neurons, GABA- and glycine-mediated synaptic signaling, neuronal development, sensory transduction including nociception, transepithelial salt transport, cell water volume control, and extracellular K+ scavenging. Not surprisingly, altered function of these proteins underlies several pathologies and hence they have become significant targets for therapeutic interventions and translational research. To study the function of these proteins we use state-of-the-art live-cell imaging microscopy and fluorescent probes for measuring and manipulating intracellular ions and water in dissociated neurons and epithelial cells. Some of these optical methods have been developed in our lab, and are used in conjunction with molecular methods, knockout models, and several microanatomical techniques.