The membrane currents of single ventricular cells were measured under whole cell voltage clamp using a giga-sealed patch electrode, and the effects of intracellular acidification were examined by perfusing the electrode pipette with different pH solutions. The plateau of the action potential was shortened when the pH of the pipette solution was lowered from the control of 7.2 to 6, and finally ...

This thesis work investigates the application of microfluidics to perform electrophysiological studies on cells, including investigations of the effect of cholesterol on the dynamic ion permeability of TRPV1 ion channels, and the application of a microfluidic device, the multifunctional pipette, in electrophysiological studies on brain slices. In the first part of this thesis, Chinese hamster o...

The sieve-pipette is the standard method for determining soil particle size distribution (PSD) because it is precise and reproducible. However, this method requires considerable time. Light diffraction methods for determining PSD are fast, but there is no standard procedure and often, results do not agree precisely with the pipette. The objective of this study was to develop a simple and fast p...

Selective suppression of protein function in the brain can be achieved using specific silencing RNAs administered in vivo. A viral delivery system is often employed to transfect neurons with small hairpin RNA (shRNA) directed against specific proteins, and intervals of several days are allowed between microinjection of the shRNA-containing virus into the brain and experiments to assess suppress...

Cells use polar molecules in the membrane to sense changes in the transmembrane potential. The opening of voltage-gated ion channels and membrane bending due to the inverse flexoelectric effect are two examples of such electromechanical coupling. We have looked for membrane motions in an electric field using atomic (or scanning) force microscopy (AFM) with the intent of studying voltage-depende...

Outer hair cells (OHC) from the organ of Corti are capable of fast voltage-induced length changes (Santos-Sacchi and Dilger, 1988), suggesting that an associated voltage sensor should reside in the OHC plasma membrane. Voltage-dependent mechanical responses and nonlinear charge movement of isolated OHCs from the guinea pig were analyzed using the whole-cell voltage-clamp technique. Ionic curren...