Book contents
- Frontmatter
- Dedication
- Contents
- Preface
- Reserved Physical Symbols and Quantities
- Abbreviations
- 1 Introduction
- 2 Charges, Currents, Fields, and Potentials in the Brain
- 3 Neural Dynamics
- 4 Volume-Conductor Theory
- 5 Conductivity of Brain Tissue
- 6 Schemes for Computing Extracellular Potentials
- 7 Spikes
- 8 Local Field Potentials (LFPs)
- 9 Electroencephalography (EEG)
- 10 Electrocorticography (ECoG)
- 11 Magnetoencephalography (MEG)
- 12 Diffusion Potentials in Brain Tissue
- 13 Final Comments and Outlook
- Appendix A Frequency-Dependent Length Constant
- Appendix B Derivation of the Current-Dipole Approximation
- Appendix C Electric Stimulation
- Appendix D Derivation of the Point-Source Equation for Anisotropic Medium
- Appendix E Statistical Measures
- Appendix F Fourier-Based Analyses
- Appendix G Derivation of Formulas for Population Signals
- Appendix H Equations for Computing Magnetic Fields
- Appendix I Derivation of the MC+ED Scheme
- References
- Index
12 - Diffusion Potentials in Brain Tissue
Published online by Cambridge University Press: 30 May 2024
Book contents
- Frontmatter
- Dedication
- Contents
- Preface
- Reserved Physical Symbols and Quantities
- Abbreviations
- 1 Introduction
- 2 Charges, Currents, Fields, and Potentials in the Brain
- 3 Neural Dynamics
- 4 Volume-Conductor Theory
- 5 Conductivity of Brain Tissue
- 6 Schemes for Computing Extracellular Potentials
- 7 Spikes
- 8 Local Field Potentials (LFPs)
- 9 Electroencephalography (EEG)
- 10 Electrocorticography (ECoG)
- 11 Magnetoencephalography (MEG)
- 12 Diffusion Potentials in Brain Tissue
- 13 Final Comments and Outlook
- Appendix A Frequency-Dependent Length Constant
- Appendix B Derivation of the Current-Dipole Approximation
- Appendix C Electric Stimulation
- Appendix D Derivation of the Point-Source Equation for Anisotropic Medium
- Appendix E Statistical Measures
- Appendix F Fourier-Based Analyses
- Appendix G Derivation of Formulas for Population Signals
- Appendix H Equations for Computing Magnetic Fields
- Appendix I Derivation of the MC+ED Scheme
- References
- Index
Summary
The diffusion of ions in the extracellular space of the brain is normally assumed to have negligible effects on extracellular potentials. However, during periods of intense neural activity or in pathological conditions such as spreading depression, concentration gradients in brain tissue can become quite pronounced, and the effects of diffusion on electric potentials cannot be a priori neglected. We here present the theory for computing diffusion potentials, and we evaluate whether diffusion potentials can become “visible” within the frequency range considered in standard LFP recordings.
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- Electric Brain SignalsFoundations and Applications of Biophysical Modeling, pp. 289 - 308Publisher: Cambridge University PressPrint publication year: 2024