Course detail
Bioelectric Phenomena
FEKT-ABEJAcad. year: 2017/2018
Physical interpretation of electric phenomena in living tissue constitutes a special area of biophysics. The subject ‚Bioelectric phenomena‘ acquaints the students with biophysical basis of the genesis of electric signals on different structural levels , with passive electric properties a of living tissue, and with currently available methods of bioelectric measurements.
Language of instruction
Czech
Number of ECTS credits
5
Mode of study
Not applicable.
Guarantor
Learning outcomes of the course unit
Passing the subject, the student is able:
- to explain genesis of membrane voltage in the living cells applying the known physical laws and to define quantities that appear in the Nernst formula for equilibrium voltages,
- to describe electrical equivalent scheme of the cell,
- to explain origin of action voltages in excitable cells and mechanism of its propagation along cell fibers,
- to describe principles of the methods of measurement of membrane voltage and membrane current,
- to characterize electrical signals recorded on cellular and molecular level and to explain their mutual relations,
- to define the terms “chemical potential’’ and ‘’electrochemical potential’’,
- to describe the relation between the propagated excitation at the level of cell and genesis of electromagnetic field in the surrounding tissue,
- to explain principles of excitation-contraction coupling in muscle cells,
- to describe origin of ECG signal as a result of action voltage propagation in the net of cardiac cells (syncytium),
- to prepare physiological solutions including measurement and adjustment of their pH, to measure tissue impedance and properties of the electrodes.
- to explain genesis of membrane voltage in the living cells applying the known physical laws and to define quantities that appear in the Nernst formula for equilibrium voltages,
- to describe electrical equivalent scheme of the cell,
- to explain origin of action voltages in excitable cells and mechanism of its propagation along cell fibers,
- to describe principles of the methods of measurement of membrane voltage and membrane current,
- to characterize electrical signals recorded on cellular and molecular level and to explain their mutual relations,
- to define the terms “chemical potential’’ and ‘’electrochemical potential’’,
- to describe the relation between the propagated excitation at the level of cell and genesis of electromagnetic field in the surrounding tissue,
- to explain principles of excitation-contraction coupling in muscle cells,
- to describe origin of ECG signal as a result of action voltage propagation in the net of cardiac cells (syncytium),
- to prepare physiological solutions including measurement and adjustment of their pH, to measure tissue impedance and properties of the electrodes.
Prerequisites
Knowledge of biology, mathematics and physics accordant with the subjects of previous bachelor’s study is expected.
Co-requisites
Not applicable.
Planned learning activities and teaching methods
Teaching methods depend on the type of course unit as specified in the article 7 of BUT Rules for Studies and Examinations.
Assesment methods and criteria linked to learning outcomes
Requirements for successful completion of the subject are specified by guarantor’s regulation updated for every academic year.
Course curriculum
A. Cellular level
1 Origin and function of electrical signals in living cells (membrane voltage, action voltage in excitable cells, propagation of action voltage, physiological significance of electrical activity)
2 Methods of measurements of membrane voltage and membrane current (electrical contacts with cell interior, technical problems and variants of their solving)
3 Physical bases of bioelectric phenomena:
Resting membrane voltage (model of the cell, electrical equivalent scheme of the cell membrane)
Action voltage (underlying mechanisms, principal components of ionic membrane current, quantitative relation between total ionic current and action voltage configuration, classification of channels from the viewpoint of time and voltage dependence, propagation of action voltage along cellular fibres)
4 Quantitative description of electrical activity of excitable cell (Hodgkin and Huxley equations for squid nerve fibres, solution under current-clamp and voltage-clamp conditions, generalization for other excitable cells, quantitative description of propagation of excitation)
5. Thermodynamic description of bioelectric phenomena (chemical and electrochemical potential, derivation of Nernst equation, Donnan equilibrium, Nernst-Planck equation, constant electrical field model)
B. Molecular level
6 Membrane ionic channels (biological membrane, structure and function of ionic channels,
gating process, drug-channel interactions, measurements of single channel currents, principle of patch clamp method, characteristics of the current recorded on molecular level)
7 Membrane ion transporting carriers (function, Na/K and Na/Ca exchangers)
C. Excitation-contraction coupling (ECC) in muscle cell
8 Structure and function of muscle, differences between types of muscle cells
9 Main structural and functional elements of ECC in cardiac cells and signalling role of Ca ions (quantitative description of transmembrane transport of calcium ions, explanation of frequency dependence of contractions )
10 Molecular processes underlying muscle contraction
D. Tissue and organ level
11 Electromagnetic field as a consequence of action voltage propagation (related clinical diagnostic methods, passive electrical properties of living tissue)
12 Biophysical background of electrocardiography (mechanism and propagation of the wave of excitation in the heart, lead systems, ECG signal, arrhythmias and natural protective mechanisms, equivalent generators of cardiac electrical field)
13 Quantitative description of the electromagnetic field generated by biological sources (application of Maxwell equations, simplifications for cardiac electrical field)
1 Origin and function of electrical signals in living cells (membrane voltage, action voltage in excitable cells, propagation of action voltage, physiological significance of electrical activity)
2 Methods of measurements of membrane voltage and membrane current (electrical contacts with cell interior, technical problems and variants of their solving)
3 Physical bases of bioelectric phenomena:
Resting membrane voltage (model of the cell, electrical equivalent scheme of the cell membrane)
Action voltage (underlying mechanisms, principal components of ionic membrane current, quantitative relation between total ionic current and action voltage configuration, classification of channels from the viewpoint of time and voltage dependence, propagation of action voltage along cellular fibres)
4 Quantitative description of electrical activity of excitable cell (Hodgkin and Huxley equations for squid nerve fibres, solution under current-clamp and voltage-clamp conditions, generalization for other excitable cells, quantitative description of propagation of excitation)
5. Thermodynamic description of bioelectric phenomena (chemical and electrochemical potential, derivation of Nernst equation, Donnan equilibrium, Nernst-Planck equation, constant electrical field model)
B. Molecular level
6 Membrane ionic channels (biological membrane, structure and function of ionic channels,
gating process, drug-channel interactions, measurements of single channel currents, principle of patch clamp method, characteristics of the current recorded on molecular level)
7 Membrane ion transporting carriers (function, Na/K and Na/Ca exchangers)
C. Excitation-contraction coupling (ECC) in muscle cell
8 Structure and function of muscle, differences between types of muscle cells
9 Main structural and functional elements of ECC in cardiac cells and signalling role of Ca ions (quantitative description of transmembrane transport of calcium ions, explanation of frequency dependence of contractions )
10 Molecular processes underlying muscle contraction
D. Tissue and organ level
11 Electromagnetic field as a consequence of action voltage propagation (related clinical diagnostic methods, passive electrical properties of living tissue)
12 Biophysical background of electrocardiography (mechanism and propagation of the wave of excitation in the heart, lead systems, ECG signal, arrhythmias and natural protective mechanisms, equivalent generators of cardiac electrical field)
13 Quantitative description of the electromagnetic field generated by biological sources (application of Maxwell equations, simplifications for cardiac electrical field)
Work placements
Not applicable.
Aims
To teach the students how to apply the knowledge acquired by previous study of physics and mathematics to understand mechanisms underlying origin of electric signals in living organisms
Specification of controlled education, way of implementation and compensation for absences
Extent and forms are specified by guarantor’s regulation updated for every academic year.
Recommended optional programme components
Not applicable.
Prerequisites and corequisites
Not applicable.
Basic literature
F. Bezanilla:Electrophysiology and the Molecular Basis of Excitability. (University of California at Los Angeles) Volně dostupné na adrese http://nerve.bsd.uchicago.edu/ (EN)
J. Šimurda: Bioelektrické jevy I, CERM Brno, 1995 (CS)
J.Šimurda, Bioelektrické jevy, elektronická skripta 2007 (CS)
S. Silbernagl, A. Despopoulos: Atlas fyziologie člověka, GRADA Publishing a.s. 2004 (CS)
J. Šimurda: Bioelektrické jevy I, CERM Brno, 1995 (CS)
J.Šimurda, Bioelektrické jevy, elektronická skripta 2007 (CS)
S. Silbernagl, A. Despopoulos: Atlas fyziologie člověka, GRADA Publishing a.s. 2004 (CS)
Recommended reading
Not applicable.
Classification of course in study plans
Type of course unit
Lecture
26 hod., optionally
Teacher / Lecturer
Syllabus
1. The origin and functions of electric signals in living cells. Membrane voltage.
2. Action voltage and its physiological significance. Propagation of action voltage down cellular fibres.
3. Possibilities of obtaining electric contact with the cell interior. Methods of measurement of membrane voltage and membrane currents.
4. Physical principles of bioelectric effects. The model of the cell for interpretation of electric effects.
5. The quantitative relationship between the overall ion membrane current and action voltage. The main components of ion membrane current and their characterisitcs.
6. Physical interpretation of propagation of excitation down cellular fibres. Biophysical description of electric effects by systems of differenetial euqations.
7. Interpretation of bioelectric effects on molecular level. The structure and functions of biological membrane.
8. Membrane channels: transitions between channel states (gating). Measurement of membrane electric currents on molecular level (the ‚patch clamp‘ method).
9. Carrier-mediated transport of ions across biological membranes. Interaction of substances with transport systems (the mechanisms of effects of some drugs and toxic substances).
10. Excitable cell as a source of electromagnetic field in the surrounding environment. Biophysical principles of electrophysiological diagnostic methods.
11. The electrocardiographic and magnetocardiographic signal as a consequence of action voltage propagation in the network of interconnected heart cells.
12. Excitation-contraction coupling in muscle cells.
13. Measurement methods of electromechanical properties of cardiac cells, tissue and heart.
2. Action voltage and its physiological significance. Propagation of action voltage down cellular fibres.
3. Possibilities of obtaining electric contact with the cell interior. Methods of measurement of membrane voltage and membrane currents.
4. Physical principles of bioelectric effects. The model of the cell for interpretation of electric effects.
5. The quantitative relationship between the overall ion membrane current and action voltage. The main components of ion membrane current and their characterisitcs.
6. Physical interpretation of propagation of excitation down cellular fibres. Biophysical description of electric effects by systems of differenetial euqations.
7. Interpretation of bioelectric effects on molecular level. The structure and functions of biological membrane.
8. Membrane channels: transitions between channel states (gating). Measurement of membrane electric currents on molecular level (the ‚patch clamp‘ method).
9. Carrier-mediated transport of ions across biological membranes. Interaction of substances with transport systems (the mechanisms of effects of some drugs and toxic substances).
10. Excitable cell as a source of electromagnetic field in the surrounding environment. Biophysical principles of electrophysiological diagnostic methods.
11. The electrocardiographic and magnetocardiographic signal as a consequence of action voltage propagation in the network of interconnected heart cells.
12. Excitation-contraction coupling in muscle cells.
13. Measurement methods of electromechanical properties of cardiac cells, tissue and heart.
Laboratory exercise
26 hod., compulsory
Teacher / Lecturer
Syllabus
1. Measurement of electric properties of metal electrodes for recording of bioelectric signals
2. Preparation and measurement of the properties of glass microelectrodes.
3. Preparation of solutions for cellular electrophysiological measurement. Measurement of pH.
4. Measurement and analysis of ion membrane currents in excitable cells (simulation experiments).
5. Measurement of excitation threshold.
6. Measurement of electric impedance in living tissue.
7. Recording of contractions in isolated heart cells.
8. Excursion to the laboratory of cellular electrophysiology
9. Electric properties of cellular membranes (numerical exercises)
10. Measurement of membrane voltage and membrane currents (seminar with demonstration)
11. Molecular basis of bioelectric effects (inatractive software)
12. Propagation of electromagnetic field generated by heart (numerical exercises)
13. Electromechanical coupling (interactive software)
2. Preparation and measurement of the properties of glass microelectrodes.
3. Preparation of solutions for cellular electrophysiological measurement. Measurement of pH.
4. Measurement and analysis of ion membrane currents in excitable cells (simulation experiments).
5. Measurement of excitation threshold.
6. Measurement of electric impedance in living tissue.
7. Recording of contractions in isolated heart cells.
8. Excursion to the laboratory of cellular electrophysiology
9. Electric properties of cellular membranes (numerical exercises)
10. Measurement of membrane voltage and membrane currents (seminar with demonstration)
11. Molecular basis of bioelectric effects (inatractive software)
12. Propagation of electromagnetic field generated by heart (numerical exercises)
13. Electromechanical coupling (interactive software)