For the first time, a patient with asymptomatic QT interval prolongation was found to carry missense mutation c.277G>A (p.Val93Ile) in KCNJ2 gene, described previously only as cause of familial form atrial fibrillation. The corresponding amino acid substitution introduced into plasmid encoding Kir2.1 channel and mutant gene expressed Chinese hamster ovary cells (CHO-K1) evaluate effect on IK1 c...

The chloride (Cl-) channel cystic fibrosis transmembrane conductance regulator (CFTR) is defective in cystic fibrosis (CF), and mutation of its encoding gene leads to various defects such as retention of the misfolded protein in the endoplasmic reticulum, reduced stability at the plasma membrane, abnormal channel gating with low open probability, and thermal instability, which leads to inactiva...

Present whole-cell patch-clamp methodology has only moderate consistency and throughput, rendering impractical functional measurements on large numbers of ion channel ligands or on large numbers of unknown or mutant channel genes. In the population patch clamp (PPC) described herein, a single voltage-clamp amplifier sums the whole-cell currents from multiple cells at once, each sealed to a sepa...

A particular characteristic of the neonatal hippocampus is the presence of spontaneous network-driven oscillatory events, the so-called giant depolarizing potentials (GDPs). GDPs depend on the interplay between GABA and glutamate. Early in development, GABA, acting on GABAA receptors, depolarizes neuronal membranes via a Cl- efflux. Glutamate, via AMPA receptors, generates a positive feedback n...

This protocol describes the loading of individual cells with fluorescent probes via patch pipettes. The patch-clamp methodology has been successfully used for single-cell dye labeling in cultured neurons, brain slices, and in vivo preparations. A broad range of dyes can be used with this loading technique. Markers for morphological reconstruction (e.g., Lucifer yellow); ion-sensitive indicator ...

The visual selection of specific cells within an ex vivo brain slice, combined with whole-cell patch clamp recording and capillary electrophoresis (CE)-mass spectrometry (MS)-based metabolomics, yields high chemical information on the selected cells. By providing access to a cell's intracellular environment, the whole-cell patch clamp technique allows one to record the cell's physiological acti...