Whole-cell recording technique

Local membrane destruction can be made by suddenly applying a short strong burst of suction. A hole is created in the cell membrane so that the pipette is in direct electrolytic contact with the cell interior. Electrical potentials and currents from the entire cell are measured and are therefore called the whole-cell recording technique. The hole may also be used to inject substances into the interior of the cell. 

Figure 1 Schematic diagrams illustrating the patch-clamp technique. (A) Overall setup for isolating single ionic channels in an intact patch of cell membrane. P = patch pipet R = reference microelectrode I = intracellular microelectrode Vp = applied patch potential Em = membrane potential Vm = Em — Vp = potential across the patch A = patch-clamp amplifier. (From Ref. 90.) (B) Five different recording configurations, and procedures used to establish them, (i) Cell attached or intact patch (ii) open cell attached patch (iii) whole cell recording (iv) excised outside-out patch (v) excised inside-out patch. Key i = inside of the cell o = outside of the cell. (Adapted from Ref. 283.)...

The electrophysiological technique used to measure changes in membrane capacitance is the patch clamp [5,6] in the whole-cell recording mode, where the plasma membrane patch in the pipet is ruptured. In another configuration of the patch clamp, the plasma membrane patch is maintained intact. In this case, small currents due to the opening of individual channels can be measured in the membrane patch. The whole-cell patch clamp... 

Whole-cell and single-channel currents. Modern techniques permit the recording of neuronal currents in response to the application of transmitters and modulators of transmission. A Averaged and summed whole-cell currents evoked by the application of glutamate... 

In isolated perfused renal tubules, concentration response curves of drugs which inhibit ion channels can be obtained with the patch clamp technique. In isolated cells of the proximal tubule, the whole-cell mode of the patch clamp technique enables the investigation of the sodium-alanine cotransport system. The apparent Km values for sodium and L-alanine can be recorded. 

Figure 16.14 Original Kca1-1 (BK) single channel recordings and the inhibitory effect of iberiotoxin. Currents were recorded from a guinea pig urinary bladder smooth muscle cell using the whole cell (cell-attached), perforated patch-clamp technique at 0 mV holding potential (Section...

There are several variations of the patch-clamp technique (Figure 16.21). Ion channel currents can be recorded from a whole cell or from small membrane pieces called excised patches, which are sections that are physically excised and removed from the cell membrane. The excised patch can be either in inside-out or outside-out configuration. The different patch-clamp configurations are described later. 

The Drosophila neuromusculature has been subject to extensive physiological investigation for more than 20 years (Jan and Jan 1976a,b Jan et al. 1997). It has been the primary tissue for the study of ionic conductances, synaptic transmission, and the output of central pattern generation. In all cases, recording has focused on the somatic muscles and the output onto these muscles by the glutamatergic NMJ. Discussed here are neuromuscular cultures derived from dissociated cells and whole-embryo culture, and recording techniques from the embryonic, larval, and adult neuromusculature in situ. 

---