The lipid bilayer plays a crucial role in gating of mechanosensitive (MS) channels. Hence it is imperative to elucidate the rheological properties of lipid membranes. Herein we introduce a framework to characterize the mechanical properties of lipid bilayers by combining micropipette aspiration (MA) with theoretical modeling. Our results reveal that excised liposome patch fluorometry is superio...

9,10-Epoxy-12-octadecenoic acid (EOA), a metabolite of linoleic acid, causes cardiac arrest in dogs. Other metabolites of linoleic acid also have toxic effects. This study investigates the mechanism of action of four of these compounds on cardiac Na(+) current (I(Na)). The whole-cell patch-clamp technique was used to investigate the effects of EOA, 9,10-dihydroxy-12-octadecenoic acid (DHOA), an...

Sour taste is mediated by acids with the degree of sourness a function of proton concentration. Recently, several members of the acid-sensing ion channel subfamily (ASICs) were cloned from taste cells and proposed to mediate sour taste. However, it is not known whether sour responses in taste cells resemble the responses mediated by ASICs. Using the whole cell patch-clamp technique and Na(+) im...

In this study we determined whether or not 5-hydroxytryptamine (5-HT) has an effect on the pacemaker activities of interstitial cells of Cajal (ICC) from the mouse small intestine. The actions of 5-HT on pacemaker activities were investigated using a whole-cell patch-clamp technique, intracellular Ca(2+) ([Ca(2+)](i)) analysis, and RT-PCR in ICC. Exogenously-treated 5-HT showed tonic inward cur...

Dielectrophoresis (DEP) offers many advantages over conventional cell assays such as flow cytometry and patch clamp techniques for assessing cell electrophysiology as a marker for cancer studies and drug interaction assessment. However, despite the advantages offered by DEP analysis, uptake has been low, remaining largely in the academic arena, due to the process of analysis being time-consumin...

Using whole-cell patch-clamp techniques in brain slices, we studied the postnatal development of electrophysiological properties of rat neocortical layer I neurons during the first three weeks of postnatal life. Neurons, including Cajal-Retzius cells, were visualized under Nomarski optics before recording. In the first postnatal week, all layer I neurons, including Cajal-Retzius cells, had low ...

The Euglycemic Hyperinsulinemic Clamp (EHC) is the most widely used experimental procedure for the determination of insulin sensitivity. In the present study, 16 subjects with BMI between 18.5 and 63.6 kg/m(2) have been studied with a long-duration (5 hours) EHC. In order to explain the oscillations of glycemia occurring in response to the hyperinsulinization and to the continuous glucose infus...

The effects of scorpion venom heat resistant protein (SVHRP) on sodium channel were studied in freshly isolated hippocampal neurons in rat using the whole-cell patch-clamp technique. The results indicated that tetrodotoxin-sensitive voltage-dependent sodium current in hippocampal neurons was inhibited by SVHRP in a dose-dependent manner. The half-inhibition concentration (IC(50)) was (0.0034+/-...

The ion channel conductances that regulate the membrane potential was investigated by using a perforated patch-clamp technique in rabbit aorta endothelial cells (RAECs). The whole-cell current/voltage (I-V) relation showed a slight outward rectification under physiological ionic conditions. The resting membrane potential was -23.3 +/- 1.1 mV (mean +/- SEM, n = 19). The slope conductances at the...

Astrocytes are neuroglial cells that exhibit functional electrical properties sensitive to neuronal activity and capable of modulating neurotransmission. Thus, electrophysiological recordings of astroglial activity are very attractive to study the dynamics of glial signaling. This contribution reports on the use of ultra-sensitive planar electrodes combined with low noise and low frequency ampl...