Cellular and Molecular Neuroscience

4.

The Action Potential

4.1.

Properties of the Action Potential

4.1.1.

4.1.2.

Rising Phase (Depolarization)

4.1.3.

4.1.4.

Falling Phase (Repolarization)

4.1.5.

Undershoot (After-hyperpolarization)

4.1.6.

All-or-None Principle

4.1.7.

Refractory Periods

4.1.7.1.

Absolute Refractory Period

4.1.7.2.

Relative Refractory Period

4.1.8.

Action Potential Duration and Shape

4.2.

The Molecular Basis of the Action Potential

4.2.1.

Voltage-Gated Sodium Channels

4.2.1.1.

Structure and Function

4.2.1.2.

4.2.1.3.

Gating and Inactivation

4.2.1.4.

4.2.1.4.1.

Tetrodotoxin (TTX)

4.2.1.4.2.

4.2.1.4.3.

Local Anesthetics

4.2.2.

Voltage-Gated Potassium Channels

4.2.2.1.

Structure and Function

4.2.2.2.

The "Delayed Rectifier"

4.2.2.3.

Channel Diversity

4.2.2.4.

A-type Potassium Channels

4.2.3.

Other Voltage-Gated Channels

4.2.3.1.

Calcium Channels

4.2.3.2.

Hyperpolarization-Activated Channels

4.3.

Action Potential Conduction

4.3.1.

Propagation Along the Axon

4.3.1.1.

Local Circuit Currents

4.3.1.2.

Unidirectional Propagation

4.3.1.3.

Cable Properties

4.3.2.

Factors Influencing Conduction Velocity

4.3.2.1.

Axonal Diameter

4.3.2.2.

4.3.2.2.1.

Effect on Capacitance and Resistance

4.3.2.2.2.

Space Constant and Time Constant

4.3.3.

Saltatory Conduction

4.3.3.1.

Role of Nodes of Ranvier

4.3.3.2.

Efficiency of Signal Transmission

4.3.3.3.

Conduction Velocity Calculations

4.4.

Action Potential Initiation

4.4.1.

Axon Initial Segment

4.4.2.

Threshold Mechanisms

4.4.3.

Integration of Synaptic Inputs

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3. The Neuronal Membrane and Electrical Potentials

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5. Synaptic Transmission