Study Guide for Chapter 4 

1.       What does it mean to say a neuron is at its resting potential? What is the neuron’s threshold?

2.       What are the primary features of an action potential? Be able to describe the events that take place during an action potential including the rising phase, overshoot, falling phase, undershoot, absolute and relative refractory periods. You should know what is happening in terms of the electrical changes, ionic changes, and conformational changes of the various gates and pumps involved.

3.       What does it mean to say that action potentials follow an all-or-none law? If action potentials follow an all-or-none law, how does a given neuron signal a larger or smaller stimulus?

4.       What determines the firing frequency of a neuron? What is the typical maximum firing frequency? What limits the maximum frequency?

5.       What is the general structure of the voltage-gated sodium channel (i.e. how many domains, how many alpha helices, and roughly how they are arranged)?

6.       What are the primary behavioral characteristics (and functional properties) of voltage-gated sodium channels?

7.       How does tetrodotoxin (TTX) affect sodium channels? What is the behavioral outcome of this effect?

8.       What is batrachotoxin and what effect does it have on neurons?

9.        What is a delayed rectifier and what does it do?

10.       What are the factors that affect the conduction velocity of an axon?

11.       How do local anesthetics such as lidocaine work?

12.     What effect do demyelinating diseases such as MS and Guillain-Barre syndrome produce? In what important way(s) are these two diseases quite different?

Key terms and review questions are on page 100.