Neurotransmitter

Neurotransmitters are chemicals in the nervous system that communicate information between neurons. Neurotransmitters are released from a presynaptic terminal of one neuron and cross the synaptic cleft (the space between neurons) before binding to a receptor on another neuron. Austrian scientist Otto Loewi discovered the first neurotransmitter, acetylcholine, in 1921 while experimenting on frogs.

Neurotransmitter Guidelines

To be considered a neurotransmitter, a chemical must meet most or all of the following criteria:

• it must be manufactured within a neuron
• it must be found in a neuron
• it must be released when a neuron is stimulated
• when it is released it must bind to a receptor and cause a biological change
• after release the chemical must become inactive
• when applied manually to post-synaptic membrane the chemical must have the same biological effect that it did when released from a neuron

Examples of Common Neurotransmitters

• Acetylcholine
• Serotonin
• Glutamate
• GABA