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Shlyonsky V. Ion permeability of artificial membranes evaluated by diffusion potential and electrical resistance measurements. ADVANCES IN PHYSIOLOGY EDUCATION 2013; 37:392-400. [PMID: 24292918 DOI: 10.1152/advan.00068.2013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In the present article, a novel model of artificial membranes that provides efficient assistance in teaching the origins of diffusion potentials is proposed. These membranes are made of polycarbonate filters fixed to 12-mm plastic rings and then saturated with a mixture of creosol and n-decane. The electrical resistance and potential difference across these membranes can be easily measured using a low-cost volt-ohm meter and home-made Ag/AgCl electrodes. The advantage of the model is the lack of ionic selectivity of the membrane, which can be modified by the introduction of different ionophores to the organic liquid mixture. A membrane treated with the mixture containing valinomycin generates voltages from -53 to -25 mV in the presence of a 10-fold KCl gradient (in to out) and from -79 to -53 mV in the presence of a bi-ionic KCl/NaCl gradient (in to out). This latter bi-ionic gradient potential reverses to a value from +9 to +20 mV when monensin is present in the organic liquid mixture. Thus, the model can be build stepwise, i.e., all factors leading to the development of diffusion potentials can be introduced sequentially, helping students to understand the quantitative relationships of ionic gradients and differential membrane permeability in the generation of cell electrical signals.
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Affiliation(s)
- Vadim Shlyonsky
- Department of Physiopathology, Université Libre de Bruxelles, Bruxelles, Belgium
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Zhang C, Raugei S, Eisenberg B, Carloni P. Molecular Dynamics in Physiological Solutions: Force Fields, Alkali Metal Ions, and Ionic Strength. J Chem Theory Comput 2010; 6:2167-75. [DOI: 10.1021/ct9006579] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Chao Zhang
- German Research School for Simulation Sciences, FZ-Juelich/RWTH Aachen University, Aachen, Germany, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, Rush University Medical Center, 1653 W. Congress Parkway, Chicago, Illinois 60612, and SISSA, CNR-INFN-DEMOCRITOS, and Italian Institue of Technology (IIT), SISSA Unit, Trieste, Italy
| | - Simone Raugei
- German Research School for Simulation Sciences, FZ-Juelich/RWTH Aachen University, Aachen, Germany, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, Rush University Medical Center, 1653 W. Congress Parkway, Chicago, Illinois 60612, and SISSA, CNR-INFN-DEMOCRITOS, and Italian Institue of Technology (IIT), SISSA Unit, Trieste, Italy
| | - Bob Eisenberg
- German Research School for Simulation Sciences, FZ-Juelich/RWTH Aachen University, Aachen, Germany, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, Rush University Medical Center, 1653 W. Congress Parkway, Chicago, Illinois 60612, and SISSA, CNR-INFN-DEMOCRITOS, and Italian Institue of Technology (IIT), SISSA Unit, Trieste, Italy
| | - Paolo Carloni
- German Research School for Simulation Sciences, FZ-Juelich/RWTH Aachen University, Aachen, Germany, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, Rush University Medical Center, 1653 W. Congress Parkway, Chicago, Illinois 60612, and SISSA, CNR-INFN-DEMOCRITOS, and Italian Institue of Technology (IIT), SISSA Unit, Trieste, Italy
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McGrath P, Kucera R, Smith W. Computer simulation of introductory neurophysiology. ADVANCES IN PHYSIOLOGY EDUCATION 2003; 27:120-129. [PMID: 12928321 DOI: 10.1152/advan.00055.2002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A computer-assisted learning (CAL) package, NeuroLab, developed for use by first-year university students undertaking professional programs in the health area, is described and evaluated. NeuroLab is a simulation of a laboratory, in which students are able to impale neurons to measure resting membrane potentials and subsequently undertake experiments including measuring resting membrane potentials, determining threshold potentials, measuring refractory periods, and examining effects on membrane potential through altering the membrane permeability to sodium and potassium ions. Students find the package to be a worthwhile learning experience, with 81 +/- 2.2% reporting the package increased their understanding of neuron function, and 78 +/- 2.5% expressing a desire for more CAL packages. Exposure to the package resulted in significantly higher mean scores in a multiple-choice question test on measuring neuron membrane potentials compared with those who were not exposed (mean scores out of 4 of 2.42 and 2.02, respectively, P < 0.001).
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Affiliation(s)
- Paul McGrath
- School of Biomedical Sciences. School of Medical Practice and Population Health, Faculty of Health, University of Newcastle, Newcastle, Australia 2308.
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