The Biophysical Approach to Excitable Systems

I. Electrical Characteristics of Membranes.- 1. Electrical Properties of Cells: Principles, Some Recent Results, and Some Unresolved Problems.- Low-Frequency Relaxation Mechanisms.- The State of Tissue Water.- References.- 2. Nonlinear Sinusoidal Currents in the Hodgkin-Huxley Model.- Hodgkin-Huxley Equations.- References.- 3. Second-Order Admittance in Squid Axon.- Linear and Nonlinear Properties of Nerve Membrane.- Properties of Linear Systems.- Theoretical Admittance of Squid Axon Membrane.- Experimental Test of Linearity.- Data Analysis.- Preparation and Electronics.- Standard Measurement of Membrane Admittance.- Linearity and Nonlinearity in the Time Domain.- Linearity and Nonlinearity in the Frequency Domain.- Dependence of Frequency Components of Membrane Current on Stimulus Amplitude.- Dependence of First- and Second-Order Currents on Stimulus Frequency and Membrane Voltage.- Dependence of First- and Second-Order Currents on Na Current.- Experimental and Theoretical Nonlinearity Compared.- Discrepancies between Theory and Experiment.- The Frequency Components of the Higher-Order Currents.- Summary.- References.- 4. Squid Axon K Conduction: Admittance and Noise during Short- versus Long-Duration Step Clamps.- Inductive Reactance in the Impedance of Squid Axon: The Frequency Domain Manifestation of Linearized Ion-Conduction Kinetics.- Advances in the Speed and Resolution of Impedance or Admittance Measurements.- Potassium Conduction Kinetics from a Comparison of Admittance and Noise Data.- Steady-State Linear Analysis of Conduction via Admittance.- Preparation and Low-Noise Voltage Clamp Technique.- Fourier Synthesized Pseudorandom Signal (FSPS).- A Method of Coherence Elimination.- The Measurement System.- The Amplitude Range for a Linear Response.- Potassium Conduction in the Calculated Admittance of Squid Axon.- Comparison of Potassium Conduction Kinetics from Admittance and Noise Data.- The Admittance and Noise of Potassium Conduction during Short- versus Long-Duration Step Clamps.- References.- 5. Squid Axon Membrane Low-Frequency Dielectric Properties.- Small Signal Electrical Equivalent of Squid Giant Axon Membrane.- On the Measurement of Membrane Capacitance and Conductance.- Membrane Capacitance and Conductance.- Complex Capacitance and Membrane Structure.- References.- II. Membrane Channels.- 6. Single-Channel Conductances and Models of Transport.- Channels in Lipid Bilayers.- Observing the Channel Conductance Fluctuations in Cell Membranes.- Direct Observation of Single-Channel Currents.- What do the Measured ? Values Tell About Transport through Open Channels?.- References.- 7. Gating Kinetics of Stochastic Single K Channels.- Chord Conductance and the Probability that a Single Channel is Open.- Instantaneous Conductance and the Driving Force for Ion Flux.- Special Cases of the Function f(E).- Rate Constants for the Gating Kinetics of Stochastic Single K Channels.- The Steady-State Probabilities for an Open K Channel.- References.- III. Membrane Transport.- 8. Calculation of the Electrogenicity of the Sodium Pump System of the Squid Giant Axon.- Method of Calculation.- Procedural Details.- Results of the Calculations.- Conclusions.- References.- 9. Depolarization and Calcium Entry.- Calcium Entry with Stimulation.- Calcium Entry with Steady Depolarization.- Calcium Entry by Na-Ca Exchange.- References.- 10. A Quantitative Expression of the Electrogenic Pump and Its Possible Role in the Excitation of Chara Internodes.- Conductances and Electromotive Forces during the Process of Inhibition of the Electrogenic Pump with 2 ?M Triphenyltin Chloride (TPC).- Internal ATP Level during TPC Poisoning.- The pH Dependence of Conductances and Electromotive Forces.- A Model for the Mechanism of Electrogenic Pump.- The pH Dependence of Pump Current.- References.- IV. Stimuli and Drugs.- 11. Increases in Membrane Conductance Caused by Electrical, Chemical, and Mechanical Stimuli.- The Role of Membrane Conductance Changes.- Ionic Channels in Membranes.- Mechanically Stimulated Changes in Membrane Conductance.- References.- 12. Continuous Stimulation and Threshold of Axons: The Other Legacy of Kenneth Cole.- From Whence We Came—How Kacy Cole and Colleagues Mapped the Geometry of Excitability Space.- Where We Are—New Results on Accommodation and Repetitive Firing.- Whither We Go—What Might “Reverse Accommodation” Mean for Neural Coding?.- References.- 13. A Model of Drug-Channel Interaction in Squid Axon Membrane.- Modified Kinetic Model.- Yohimbine.- QX-314.- Discussion.- Summary.- References.