Modelling the extracellular potential generated by a muscle fiber as the output signal of a convolutional system

Adv Physiol Educ. 2024 Apr 11. doi: 10.1152/advan.00238.2023. Online ahead of print.ABSTRACTA central topic in Bioelectricity is the generation of the extracellular potential that results from the propagation of a transmembrane action potential along the muscle fiber. However, the way in which the extracellular potential is determined by the propagating action potential is difficult to describe, conceptualize and visualize. Moreover, traditional quantitative approaches aimed at modelling extracellular potentials involve complex mathematical formulations, which do not allow students to visualize how the extracellular potential is generated around the active fiber. The present study is aimed at presenting a novel pedagogical approach to teaching the generation of extracellular potentials produced by muscle fibers based on the convolution operation. The effectiveness of this convolutional model was tested using a written exam and a satisfaction survey. Most students reported that a great advantage of this model was that it simplifies the problem by dividing it into three distinct components: (i) the input signal (associated to the action potential), (ii) the impulse response (linked to the system formed by the fiber and the recording electrode), and (iii) the output signal (the extracellular potential). Another key aspect of the present approach was that the input signal was represented by a sequence of electric dipoles, which allowed students to visualize the individual contrib...
Source: Advances in Physiology Education - Category: Physiology Authors: Source Type: research