The recording of potentials from motoneurones with an intracellular electrode
Year: 1952
Type: article
Abstract: Graham & Gerard (1946) first developed the technique of penetrating frog muscle fibres by an extremely fine glass tube filled with saline, which thus served as an internal micro-electrode by which the potential ofthe interior ofthe fibre could be measured relative to its exterior. Using this same technique and with micro-electrodes less than l,u in external diameter, Ling & Gerard (1949), Nastuk & Hodgkin (1950), Nastuk (1950) and Fatt & Katz (1950 a) have re-ported precise and detailed investigations on the resting and action potentials of frog muscle fibres. The significance of these investigations has been established by two important observations of Nastuk & Hodgkin (1950); the recorded potential difference is restricted to the very tenuous surface membrane of the muscle fibre, the interior being virtually isoelectric; and the puncture of the cell membrane by the micro-electrode does not appreciably alter the potential recorded by a closely adjacent micro-electrode. Apparently the membrane seals itself around the penetrating glass tube, so eliminating the drain of membrane current through the punctured hole. This glass micro-electrode technique has been extended successfully to several other excised tissues: giant axons of Sepia (Weidmann, 1951); frog heart muscle (Woodbury & Woodbury, 1950); mammalian heart muscle (Draper & Weidmann, 1950, 1951); frog and mammalian nerve fibres (Woodbury & Woodbury, 1950); frog dorsal root ganglion cells (Svaetichin, 1951). Weidmann (1951) reported that the results with the micro-electrode on Sepia axons were virtually identical with those obtained by the earlier technique employed on giant axons using an internal electrode inserted from the cut end. The present paper reports an investigation in which glass micro-electrodes have been successfully introduced into mammalian motoneurones in the spinal cords of anaesthetized cats. When using the mIhicruder technique of
Source: The Journal of Physiology
Authors: L. G. Brock, J. S. Coombs, J. C. Eccles
Language: English
Subfield: Cellular and Molecular Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2098749676