Patch clamp recording whole cell currents

Figure 13.3 Whole-cell patch-clamp recordings of excitatory postsynaptic currents (EPSCs) from dorsal horn neurons of rat (prenatal P2-13) spinal cord slices. The normal evoked EPSC of about 160pA obtained by focal stimulation of nearby tissue was dramatically reduced by addition of a cocktail (CABS) of CNQX 10 pM, D-APV 50 pM, bicuculline 10 pM and strychnine 5 pM to block glutamate, GABAa and glycine receptors. The small residual EPSC shown was blocked by the ATP P2 receptor antagonist suramin and is therefore probably mediated by released ATP. (Prom Bardoni et al. 1997 and reproduced by permission of the Journal of Neuroscience)...

Hoyer J, Gogelein H (1991) Sodium-alanine cotransport in renal proximal tubule cells investigated by whole-cell current recording. J Gen Physiol 97 1073-1094 Merot J, Bidet M, Gachot B et al. (1988) Patch clamp study on primary culture of isolated proximal convoluted tubules. Pfliigers Arch. 413 51-61... 

The patch electrode voltage-clamp is the method of choice to study V, alterations (Hamill et al., 1981). However, the high resistance seals required for these studies are not readily formed on mammalian sperm due both to geometric factors as well as the low compliance of the plasma membrane (Arnoult et al., 1996b). To date, recordings of whole cell currents, as is essential for monitoring of V, have not been reported in sperm, despite the heroic efforts exerted to obtain excised patches from these cells (Espinosa et al., 1998). As an alternative, has been ex-... 

Figure 2. A. Recording of calcium variations in a photocyte cluster of O. aranea. (i) 200mM KCl stimulation, ( (>) rinsing with ASW. Values are expressed as a ratio between Ca bound fura-2 and free fura-2. B. Whole cell patch-clamp recording on O. californica photocyte. Stimulation protocol holding potential of-lOOmV, steps of 25mV from -lOOmV to -i-lOOmV (a) outward current, (b) inward current...

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... 

In order to confirm the possible interaction of ethanol and crocin on NMDA receptors, we also performed whole-cell patch recording with primary cultured hippocampal neurons and measured membrane currents induced by the application of NMDA in a voltage-clamped condition. Application of 100 pM NMDA induced an inward current of 100.2 9.8 pA (n=10) at a holding potential of -60 mV. The NMDA-induced inward current was not affected by 10 pM CNQX (data not shown), but was completely abolished by 30 pM APV, supporting the fact that the response was mediated by NMDA receptors. Ethanol inhibited NMDA-induced currents in a concentration-dependent manner. Crocin (10 pM) had no effect on NMDA-induced currents by itself (data not shown), but attenuated the inhibitory effect of ethanol on NMDA-induced currents. The concentration-effect curve for ethanol was shifted to the right by the presence of crocin [22]. 

Figure 2. Currents recorded from a cultured, embryonic cockroach brain neuron intracellularly perfused and voltage-clamped using the whole cell patch method. The intra-electrode [Cl"] was 114 mV and [C1"]Q was 221 mM. For this ratio of [Cl-] across the cell membrane, the Nernst equation predicts a value of -16 mV for the Cl" equilibrium potential...

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. 

---