GENESIS OF ACTION POTENTIALS IN EXCITABLE TISSUES.
Final scientific rept. 1 May 66-30 Apr 67,
UPPSALA UNIV (SWEDEN) INST OF PHYSIOLOGY AND MEDICAL BIOPHYSICS
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The work was concerned with the nature of the possible coupling between electrochemical and hydrostatic forces in excitable cell membranes and on the nature of selectivity properties of gel polymer cell models. 1 A model for mechanoelectrical transduction was investigated on the electrohydraulic nerve analog. The problems were centered on the definition of the threshold concepts. By means of analog computation and methods from non-linear mechanics a certain clarification was obtained in terms of the electrical stimulus intensity, the prevailing hydrostatic membrane pressure differential and the time history of the system. The difference in the effects of suprathreshold and subthreshold stimuli was elucidated. These studies may be of importance in a future analysis of the behavior of biological mechanoreceptors and for the understanding of the pacemaker action in the heart in normal and arrhythmical conditions. 2 Studies on living objects were performed on isolated frog hearts, demonstrating that the mechanical distension may be of importance for the heart excitability, indicating a possible coupling between electrochemical and pressure forces. Excitability theories predict also a water transfer across the excitable membranes during excitation. Experiments on the isolated crayfish axons showed the possibility of a marked water transfer. 3 In order to elucidate the nature of the differential, selective ion permeability properties, characteristic for living cell membranes, some preliminary work was done on parametric ion pumping on artificial membranes. 4 An extensive report was made on the selectivity properties of ions and non-electrolytes in gel polymers. Author
- Anatomy and Physiology