Perforated-patch

Takens-Kwak BR, Jongsma HJ, Rook MB, Van Ginneken AC Mechanism of heptanol-induced uncoupling of cardiac gap junctions A perforated patch-clamp study. Am J Physiol 1992 262 C1531-C1538. 

Owens DF, Boyce LH, Davis MB, Kriegstein AR (1996) Excitatory GABA responses in embryonic and neonatal cortical slices demonstrated by gramicidin perforated-patch recordings and calcium imaging. J Neurosci 16 6414-23... 

Perforated patch records suggest that about 10-25% of total K+-ATP conductance is activated at rest in mouse B-cells (Ashcroft and Rorsman, 1989) and rather less (about 4%) in rat B-cells (Cohen et al., 1990). Cell-attached patch recordings have established that 50% of the channels are inhibited at 2mM glucose and more than 90% at 5 mM (Misler et al., 1986 Ashcroft et al., 1988 Rorsman and Trube, 1990). For depolarization only the ATP-sensitive K+ channels are responsible. This means that closure occurs when the intracellular ATP and/or the intracellular ATP/ADP ratio (Section 3.3.4) increases in response to increased nutrient (mainly glucose) metabolism (Fig. 17). 

The impact of different pharmacological compounds has been evaluated on hESC- or iPS-derived cardiomyocytes using Image Xpress Micro and FLIPR Tetra systems [111], impedance-based xCELLigence real-time cell analyzer Cardio system [112, 113], MEA [54, 114], and perforated patch clamp [38], The impact of cardiotoxic drugs on the release of biomarkers, such as troponin T and fatty acid-binding protein 3 from cardiomyocytes, has also been investigated to predict the cardiotoxicity [115]. 

Strichart I have some concern about the steady state levels of phosphorylation being very dependent on the activity of phosphatases. I wonder whether these experiments should be repeated with perforated patch or cell-attached patches, because of the possibility of a much larger or smaller effect as a result of the inevitable perfusion that occurs. Does anyone know anything about the effects of the intracellular media that we choose They are pretty much the same. 

Bean It is extremely difficult to do Na+ channel voltage clamping with perforated patch recordings. It is hard to get the series resistance down low enough to get a good clamp. 

Horn In perforated patches it tends to be relatively stable. 

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...

Korn, S.J. and Horn, R. (1989) Influence of sodium-calcium exchange on calcium current rundown and the duration of calcium-dependent chloride currents in pituitary cells, studied with whole cell and perforated patch recording. Journal of General Physiology, 94 789-812. 

Aldea M, Jun K, Shin HS, Andres-Mateos E, Solis-Garrido LM, Montiel C, Garcia AG, AlhiUos A. A perforated patch-clamp study of calcium currents and exocytosis in chromaffin ceUs of wUd-type and alpha(lA) knockout mice. JNeurochem 2002 81(5) 911-21. 

Fig. 3 Spontaneous action potentials recorded from freshly-isolated single Tbxl8-VMs (n=5, middle panel) with perforated-patch current-clamp technique, showing robust and rhythmic APs with prominent diastolic depolarization recapitulating the electrophysiological hallmark of native SAN myocytes (left panel). The same recordings are expanded in the lower panel to show prominent diastolic depolarization in Tbxl8-VMs and native SAN myocytes. Right panel GFP-VMs displayed stable resting membrane potential and fired single action potential only upon electrical stimulation.

In this section, variations of the patch-clamp technique are mentioned. Among the different variations on the patch-clamp technique, probably the most relevant are loose patch-clamp, perforated patch-clamp, giga-patch recordings, and thin-slices patch-clamp. 

Stea A, Nurse CA. Whole-cell and perforated-patch recordings from 02-sensitive rat carotid body cells grown in short- and long-term culture. Pflligers Arch 1991 418(l-2) 93-101. 

Figure 2 Characterization of TASKl in rat cerebellar granule neurons, (a) Subtracted currents evoked by ramp hyperpolarizations from a resting potential of —20 mV to —100 mV on the time scale on the X-axis showing the acid- and hypoxia-sensitive components as indicated. Also shown is the negligible component that is h poxia-sensitive under acidic conditions, (b) Exemplar time course of acid and hypoxia sensitivity of currents measured at —20 mV (c) Current clamp recording of the effect of hypoxia on membrane potential. All recordings were made employing the perforated patch technique.

Figure 3 Effects of various stimuli and mitochondrial inhibitors on the resting membrane potential of quiescent chromaffin cells. A typical example of hypoxia-induced membrane depolarization is shown in (a), using nystatin perforated-patch whole-cell recording. In (b), bicuculline (100 pM), a reversible inhibitor of small-conductance Ca +-dependent K+ channels (SK), also caused membrane depolarization similar to hypoxia. The mitochondrial inhibitors 2,4-drnitrophenol (DNP) and cyanide (CN) did not mimic the h poxia-mduced membrane depolarization seen in (c) and (d), respectively in fact, in (d), CN caused membrane h3q)erpolarization, though in most cases no change in membrane potential was observed. Both DNP and CN were usually without effect even after perfusing the drug for >10 min. In (e), the hyperpolarizing effect of CN was reversed in the presence of 200 pM glibenclamide, a blocker of Katp channels.

Figure 4 Properties of single versus clustered neonatal rat chromaffin cells, (a) T3Tosine hydroxylase (TH)-positive immunofluorescence of chromaffin cells in culture note the presence of small clusters and occasional single isolated cells. Perforated-patch recordings of membrane potential revealed that single cells tended to he quiescent (h), whereas cells in clusters tended to fire spontaneous action potentials at room temperatine (c).

Korn S., Mary A., Connor J., and Horn R. 1991. Perforated patch recording. Methods Neurosci. 4 264-373. 

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