3.1 Communication in the Nervous System (Outline)
- Why does cocaine (and "speed" [= methamphetamine]) make some people feel very euphoric and some people very crazy?
- Why do some runners report that they feel extraordinarily good after a very long run?
- Why do soldiers in war who have been wounded sometimes not actually realize they've been hurt?
- What is multiple sclerosis? What is Parkinson's disease?
- When the Syrian Army was reported to use nerve gas (a chemical weapon) against women and children during the current civil war, why did it kill many of the people who breathed the gas?
- How are eating disorders possibly related to some types of suicidal acts?
1. Nervous Tissue: The Basic Hardware
2. The Neural Impulse: Using Energy to Send Information
Neuron at Rest = A Tiny Battery
- Resting potential = "a neuron's stable, negative charge when the cell is inactive"
- Resting Potential of the Neuron = -70mV
B. The Action Potential = Movement of Ions In/Out of Neuron
- Action potential = "a very brief shift in a neuron's electrical charge that travels along an axon"
- Threshold of Excitation @ -40mV
- Depolarization (move from -70mV to +40/50 mV)
- Repolarization (move from +40/50 mV to -90 mV)
- Hyperpolarization (when the voltage goes below -70mV)
- Absolute Refractory Period
- Here is an excellent YouTube video (#013 A Review of the Action Potential from Interactive Biology)
C. All-or-None Law
3. The Synapse: Where Neurons Meet
Neurotransmitters and Behavior