Electrophysiology patch-clamp recording

Hardy A, Ptdouzier-Paulignan B, Duchamp A, Royet JP, Duchamp-Viret P. 2005. 5-hydroxytryptamine action in the rat olfactory bulb In vitro electrophysiological patch-clamp recordings of juxtaglomerular and mitral cells. Neuroscience 131 717-731. 

The main procedure to relate the electrophysiological properties of cortical neurons to their morphological features is represented by the whole-cell patch clamp recording on slices maintained in vitro. The detailed description of this procedure is beyond the purpose of the present chapter. However, a brief overview of the main steps involved is given below. 

Electrophysiological Experiments. Guinea pig myocardial cells prepared as described previously 24) were superfused at 37 C with a Tyrode solution. Electrical properties of the myocytes were examined by the patch-clamp methods (25) using fire-polished pipettes. The current was measured by means of a patch-clamp amplifier, stored on the tape through a digital PCM data recording system, and analyzed with a computer. 

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... 

Hamill OP (1993) Cell-free patch clamp. In Kettenmann H, Grantyn R (eds) Practical Electrophysiological Methods. Wiley and Sons, New York, pp 284-288 Hamill OP, Marty A, Neher E, Sakmann B, Sigworth FJ (1981) Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches. Pfltiger s Arch 391 85-100... 

Two methods were used to study the effect of cannabinoids on presynaptic axon terminals. The more frequently used electrophysiological approach measures neurotransmission. In hrain slices or neuronal cultures, electrical currents in postsynaptic neurons are recorded with patch-clamp or microelectrode techniques. Presynaptic axon terminals are electrically stimulated and the postsynaptic current resulting from stimulation of ligand-gated ion channels of postsynaptic neurons hy the released transmitter is determined. The change in the postsynaptic current amplitude is a measure of the change in synaptic transmission. 

Studies on the effects of OPs/CMs have been performed with various preparations, including brain slices, cultured neurons, acutely isolated neurons, iieuroreceptors expressed in a host cell, and neuronal cell lines. The electrophysiologi-cal techniques utilized are extracellular recording, intracellular recording, and patch clamp. Similar to the studies of neuromuscular functions, various compounds were tested. Thus, it i.s extremely difficult to obtain a unified picture regarding the mechani,sm of action of OPs/CMs on. synaptic transmission. 

Electrophysiology Recordings To record currents from sealed cells, the silicon chip assembly was used as a chamber for a voltage clamp setup (Fig. 6). Each half of the chamber (top and bottom) was connected to the electrodes of a headstage. The top chamber was connected to the input of the patch clamp amplifier, and the bottom chamber was connected to either the ground or the command voltage depending on the amplifier used. 

We have studied the electrophysiological properties of outer mitochondria membranes incorporated in liposomes, using the patch-clamp technique. The proteoliposomes were prepared and enlarged in 150 mM KCl, 0.1 mM CaCh, and 20 mM HEPES, and the same solution was used in the recording pipette. Liposome-attached and inside-out patches were obtained. 

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