Electrophysiology of an Insect Heart
Open Access
- 1 March 1963
- journal article
- research article
- Published by Rockefeller University Press in The Journal of general physiology
- Vol. 46 (4) , 803-821
- https://doi.org/10.1085/jgp.46.4.803
Abstract
Bioelectric activity in single cells of the moth myocardium has been measured in situ with intra-cellular microelectrodes with particular reference to the bizarre ionic medium which bathes the tissues. Resting potentials averaged 47 mv, inside negative with respect to outside, despite a value of 11 mv calculated on the basis of transmembrane potassium concentration gradients. Action potentials overshoot as much as 12 mv in the virtual absence of extracellular sodium. Two "types" of action potentials have been recorded; one that resembles vertebrate atrial action potentials is found in the cephalic region of the tubular heart, and the other, similar in contour to vertebrate ventricular action potentials, is found in the areas posterior to the first abdominal segment. Histological sections indicate no structural differences between the two areas. Typical cardiac pacemaker type potentials occur but are not topographically localized. The effects of the omission from the perfusion fluid of the four major cationic constituents, Na+, K+, Ca++, and Mg++, on resting and action potentials may be summarized as no effect, hyperpolarization, prolonged repolarization, and depolarization, respectively.Keywords
This publication has 18 references indexed in Scilit:
- Studies on the Flight Mechanism of InsectsThe Journal of general physiology, 1961
- The sodium‐potassium hypothesis as the basis of electrical activity in frog ventricleThe Journal of Physiology, 1960
- Electrophysiological evidence for specialized fiber types in rabbit atriumAmerican Journal of Physiology-Legacy Content, 1959
- DIGOXIN, OUABAIN AND POTASSIUM MOVEMENTS IN RABBIT AURICLESBritish Journal of Pharmacology and Chemotherapy, 1957
- The effect of ions upon neuromuscular transmission in a herbivorous insectThe Journal of Physiology, 1957
- Effect of Several Cations on Transmembrane Potentials of Cardiac MuscleAmerican Journal of Physiology-Legacy Content, 1956
- [Effects of hyposodic solutions on the cellular potentials of cardiac tissue of mammals].1956
- THE BEHAVIOR OF ISOLATED HEARTS OF THE GRASSHOPPER, CHORTOPHAGA VIRIDIFASCIATA, AND THE MOTH, SAMIA WALKERI, IN SOLUTIONS WITH DIFFERENT CONCENTRATIONS OF SODIUM, POTASSIUM, CALCIUM, AND MAGNESIUMThe Journal of general physiology, 1954
- A quantitative description of membrane current and its application to conduction and excitation in nerveThe Journal of Physiology, 1952
- Cardiac resting and action potentials recorded with an intracellular electrodeThe Journal of Physiology, 1951