Control of glass microelectrodes for intracellular recordings

Résumé Une méthode pour vider et examiner des microélectrodes de verre au microscope électronique est décrite. On a trouvé une corrélation entre le diamètre du bout et la résistance électrique. Le diamètre de l'extrémité des électrodes dépend du procédé de remplissement et les meilleurs résultats sont obtenus par la méthode deTasaki modifiée.     

Measurement of glass microelectrodes

Zusammenfassung Zur Untersuchung der elektrischen Zellmembraneigenschaften sind bekanntlich besonders scharfe Glaselektroden Voraussetzung. Mit Hilfe eines modifizierten Elektronenmikroskops kann sowohl Wandbreite, wie auch innerer Durchmesser der Mikroelektrodenspitze gemessen werden.     

Fine tipped metal microelectrodes with glass insulation

Zusammenfassung Es wird eine Methode beschrieben, die es ermöglicht, glasisolierte Platinelektroden mit beliebig feiner Spitze herzustellen.     

Techniques for making capillary microelectrodes

Résumé Nous décrivons un appareil facile à construire pour étirer des microélectrodes capillaires et une manière simple de remplir ceux-ci sous pression réduite.

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This work was supported by a research grant from the National Institute of Neurological Diseases and Blindness, U. S. Public Health Service.     

A simplified method for silanization of doublebarrelled ion-sensitive microelectrodes

Summary A simplified procedure is described for silanization of one shank of a doublebarrelled microelectrode. this procedure makes it possible to make more functioning electrodes in a shorter time.     

Identification using glass microelectrodes of the activities recorded in the neighborhood of axons and cell bodies of the trigeminal sensory complex]

Using glass micropipettes unitary activities were recorded at the level of the trigeminal sensory complex. Iontophoresis of pontamine blue allowed us to localise the recording loci. Two types of spikes were observed, they were distinguished on the basis of their shape: one corresponds to an axon spike, the other to a cell body spike.     

Photodynamic effect of dye on frog muscle fibre using microelectrodes

Zusammenfassung Kurarisierte und nichtkurarisierte Frosch-Sartorii zeigten einen veränderlichen Grad der Depolarisation, wenn sie mit Bengalrot (1:25 000) gefärbt und durch scharf zentriertes Licht einer 300-Watt-Tungsten-Lampe beleuchtet wurden. Die Depolarisation wurde niemals im äusseren Natrium und ohne Sauerstoff beobachtet.     

A simple system for mechanical and electrical recordings from frog nerve-muscle preparation

Summary A device is described which can be used for simultaneous measurement of the muscle action potential and the contraction of the frog gastrocnemius nerve-muscle preparation. The apparatus is characterized by ease of construction, good accuracy and reliability.We thank Ms.C. Friedemann for preparation of the drawings; Ms.A. Middelmann for technical assistance.     

A simple system for mechanical and electrical recordings from frog nerve-muscle preparation.

A device is described which can be used for simultaneous measurement of the muscle action potential and the contraction of the frog gastrocnemius nerve-muscle preparation. The apparatus is characterized by ease of construction, good accuracy and reliability.     

Cell-penetrating peptides: tools for intracellular delivery of therapeutics

The main problem of therapeutic efficiency lies in the crossing of cellular membranes. Therefore, significant effort is being made to develop agents which can cross these barriers and deliver therapeutic agents into cellular compartments. In recent years, a large amount of data on the use of peptides as delivery agents has accumulated. Several groups have published the first positive results using peptides for the delivery of therapeutic agents in relevant animal models. These peptides, called cell-penetrating peptides (CPPs), are short peptides (fewer than 30 residues) with a net positive charge and acting in a receptor- and energy-independent manner. Here, we give an extensive review of peptide-mediated delivery systems and discuss their applications, with particular focus on the mechanisms leading to cellular internalization.Received 14 March 2005; received after revision 25 April 2005; accepted 28 April 2005     

Evidence for the intracellular accumulation of anandamide in adiposomes

Anandamide is a lipid messenger that carries out a wide variety of biological functions. It has been suggested that anandamide accumulation involves binding to a saturable cellular component. To identify the structure(s) involved in this process, we analyzed the intracellular distribution of both biotinylated and radiolabeled anandamide, providing direct evidence that lipid droplets, also known as adiposomes, constitute a dynamic reservoir for the sequestration of anandamide. In addition, confocal microscopy and biochemical studies revealed that the anandamide-hydrolase is also spatially associated with lipid droplets, and that cells with a larger adiposome compartment have an enhanced catabolism of anandamide. Overall, these findings suggest that adiposomes may have a critical role in accumulating anandamide, possibly by connecting plasma membrane to internal organelles along the metabolic route of this endocannabinoid. S. Oddi, F. Fezza: These authors contributed equally to the study.     

Use of peroxidase-avidin conjugate for the demonstration of intracellular antigen

Summary Horseradish peroxidase was coupled to avidin by periodate oxidation. Using the peroxidase-avidin conjugate together with biotin-labeled anti-chymotrypsinogen antibody, chymotrypsinogen was clearly demonstrated in the zymogen granules of the pancreas. The reaction between avidin and biotin is so rapid and stable that the avidin-biotin system can be effectively applied to immunohistochemical studies.This work was supported by Grant-in-Aid for Scientific Research from The Ministry of Education, Science and Culture, The Japanese Government, No. 448086.     

Caveolin regulation of neuronal intracellular signaling

Caveolin proteins physically interact with and compartmentalize membrane-localized signaling proteins to facilitate high-fidelity intracellular signaling. Though primarily studied outside the nervous system, recent investigations have revealed that caveolin proteins are key modulators of a variety of neuronal intracellular signaling pathways. Through both protein aggregation and segregation, caveolin proteins can exert positive and negative influences on intracellular signaling. This review will detail recent findings regarding caveolin function in the brain.