Voltage Offsets in Patch-Clamp Experiments

1995 ◽  
pp. 147-153 ◽  
Author(s):  
Erwin Neher
Keyword(s):  
Patch Clamp

High-voltage electron microscopy of patch-clamped membranes

1987 ◽  
Vol 45 ◽  
pp. 582-583
Author(s):  
F. Sachs ◽  
M. J. Song
Keyword(s):  
Electron Microscopy ◽  
Cell Membrane ◽  
Patch Clamp ◽  
High Voltage Electron Microscopy ◽  
Small Patch ◽  
Cellular Electrophysiology ◽  
Voltage Electron ◽  
Electron Microscopes ◽  
Patch Technique ◽  
Membrane Patch

Cellular electrophysiology has been revolutionized by the introduction of patch clamp techniques. The patch clamp records current from a small patch of the cell membrane which has been sucked into a glass pipette. The membrane patch, a few micons in diameter, is attached to the glass by a seal which is electrically, diffusionally and mechanically tight. Because of the tight electrical seal, the noise level is low enough to record the activity of single ion channels over a time scale extending from 10μs to days. However, although the patch technique is over ten years old, the patch structure is unknown. The patch is inside a glass pipette where it has been impossible to see with standard electron microscopes. We show here that at 1 Mev the glass pipette is transparent and the membrane within can be seen with a resolution of about 30 A.

Measurement of spontaneous neuronal membrane activity by time lapse confocal microscopy

1995 ◽  
Vol 53 ◽  
pp. 972-973
Author(s):  
R H. Selinfreund ◽  
A. H. Cornell-Bell
Keyword(s):  
Membrane Potential ◽  
Confocal Microscopy ◽  
Patch Clamp ◽  
Electrical Activity ◽  
Time Lapse ◽  
Neuronal Firing ◽  
Neuronal Membrane ◽  
Pituitary Cells ◽  
Patch Clamp Recording ◽  
Spontaneous Electrical Activity

Cellular electrophysiological properties are normally monitored by standard patch clamp techniques . The combination of membrane potential dyes with time-lapse laser confocal microscopy provides a more direct, least destructive rapid method for monitoring changes in neuronal electrical activity. Using membrane potential dyes we found that spontaneous action potential firing can be detected using time-lapse confocal microscopy. Initially, patch clamp recording techniques were used to verify spontaneous electrical activity in GH4\C1 pituitary cells. It was found that serum depleted cells had reduced spontaneous electrical activity. Brief exposure to the serum derived growth factor, IGF-1, reconstituted electrical activity. We have examined the possibility of developing a rapid fluorescent assay to measure neuronal activity using membrane potential dyes. This neuronal regeneration assay has been adapted to run on a confocal microscope. Quantitative fluorescence is then used to measure a compounds ability to regenerate neuronal firing.The membrane potential dye di-8-ANEPPS was selected for these experiments. Di-8- ANEPPS is internalized slowly, has a high signal to noise ratio (40:1), has a linear fluorescent response to change in voltage.

Transferrin-induced endocytosis in stably transfected HeLa cells expressing wild-type and C282Y-mutant HFE measured by patch-clamp capacitance techniques

2001 ◽  
Vol 120 (5) ◽  
pp. A564-A565
Author(s):  
L SCHWAKE ◽  
A HENKEL ◽  
H RIEDEL ◽  
B HADASCHIK ◽  
T SCHLENKER ◽  
...  
Keyword(s):  
Patch Clamp ◽  
Hela Cells ◽  
Wild Type

Cannabinoide und neurale Signalübertragung

2004 ◽  
Vol 50 (5) ◽  
pp. 297-308
Author(s):  
Ilka Wallmichrath ◽  
Bela Szabo
Keyword(s):  
Patch Clamp ◽  
G Protein ◽  
Präsynaptische Hemmung

<B>Fragestellung:</B> Der primäre Angriffspunkt von Cannabinoiden im Nervensystem ist der G-Protein gekoppelte CB1-Cannabinoidrezeptor. Er ist im zentralen und peripheren Nervensystem weit verbreitet. Unser Ziel war es, zu klären, wie Cannabinoide die synaptische Übertragung zwischen Neuronen beeinflussen. Die Rolle von endogenen Cannabinoiden (Endocannabinoiden) bei der synaptischen Übertragung wollten wir ebenfalls charakterisieren. </P><P> <B>Methodik:</B> Die Mehrzahl der Untersuchungen wurden mit elektrophysiologischen Methoden, insbesondere der Patch-Clamp-Technik, an Hirnschnitten durchgeführt. </P><P> <B>Ergebnisse:</B> Die am häufigsten beobachtete neuronale Wirkung von Cannabinoiden war die Hemmung der synaptischen Übertragung. Aktivierung von CB1-Rezeptoren hemmte die Freisetzung verschiedener Transmitter aus ihren präsynaptischen Axonterminalen. Auch Endocannabinoide, die im postsynaptischen Neuron synthetisiert wurden, hemmten die Transmitterfreisetzung aus dem präsynaptischen Axonterminal. </P><P> <B>Schlussfolgerungen:</B> Die präsynaptische Hemmung der Neurotransmitterfreisetzung durch Cannabinoide ist ubiquitär im Nervensystem. Eine neue Form der Kommunikation zwischen Neuronen ist die Hemmung der Neurotransmission durch Endocannabionoide, die aus dem postsynaptischen Neuron freigesetzt werden.

An Anthrone-Based Kv7.2/7.3 Channel Blocker with Improved Properties for the Investigation of Psychiatric and Neurodegenerative Disorders

2019 ◽  
Author(s):  
Jacob Porter ◽  
Oscar Vivas-Rodriguez ◽  
C. David Weaver ◽  
Eamonn Dickson ◽  
Abdulmohsen Alsafran ◽  
...  
Keyword(s):  
Patch Clamp ◽  
Neurodegenerative Disorders ◽  
Channel Blocker ◽  
Optimal Combination ◽  
Channel Blockers ◽  
Enolate Alkylation ◽  
Cyp Inhibition ◽  
Alkylation Reactions ◽  
Metabolic Instability

A set of novel Kv7.2/7.3 (KCNQ2/3) channel blockers was synthesized to address several liabilities of the known compounds XE991 (metabolic instability and CYP inhibition) and the clinical compound DMP 543 (acid instability, insolubility, and lipophilicity). Using the anthrone scaffold of the prior channel blockers, alternative heteroarylmethyl substituents were installed via enolate alkylation reactions. Incorporation of a pyridazine and a fluorinated pyridine gave an analog (JDP-107) with an optimal combination of potency (IC<sub>50</sub>= 0.16 𝜇M in a Kv7.2 thallium flux assay), efficacy in a Kv7.2/7.3 patch clamp assay, and drug-like properties.

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