Lecture 06

Brain 3

1. Synaptic Transmission
1. Otto Loewi's Dream
2. Synaptic Transmission
2. Major Neurotransmitters
3. Psychoactive Drugs

Overview

Scientists once believed that neurons physically touch one another and communicate with electrical signals, but in an experiment that allegedly came to him in a dream, Otto Loewi first showed that neurons communicate through the exchange of chemicals, not through electrical signals. These chemicals are now known as neurotransmitters.

Nearly 100 neurotransmitters have been identified, but 6 important ones were discussed in lecture. These chemicals have different effects depending on the receptor site of the neighboring axon.

Psychoactive drugs are exogenous substances that affect psychological phenomena by altering the normal transfer of a neurotransmitter. This disruption can occur during any of four stages.

Specifics

1. Be familiar with Otto Loewi's experimental demonstration that neurons communicate chemically.
2. Describe the role that calcium plays in synaptic transmission.
3. Be able to identify six major neurotransmitters and some of their dominant effects.
4. Describe four stages during which psychoactive drugs can alter the transmission of neurotransmitters, and be familiar with how two drugs, Prozac and cocaine, achieve their effects.