Chapter 3 Outline

Introduction: Stimulating Conversation

PART I  Electric Neurons

Electrical Signals Are the Vocabulary of the Nervous System

A threshold amount of depolarization triggers an action potential

Ionic mechanisms underlie the action potential

Action potentials are actively propagated along the axon

BOX 3.1: How Is an Axon Like a Toilet?

SIGNS & SYMPTOMS: Multiple Sclerosis

Synapses cause local changes in the postsynaptic membrane potential

Spatial summation and temporal summation integrate synaptic inputs

PART II  Synaptic Transmission

Synaptic Transmission Requires a Sequence of Events

Action potentials cause the release of transmitter molecules into the synaptic cleft

Receptor molecules recognize transmitters

The action of synaptic transmitters is stopped rapidly

Neural circuits underlie reflexes

PART III  Gross Potentials

EEGs Measure Gross Electrical Activity of the Human Brain

Electrical storms in the brain can cause seizures

RESEARCHERS AT WORK: Surgical probing of the brain revealed a map of the body