Acetylcholine, the chief and first-recognized neurotransmitter, acts as a stimulant to the skeletal muscles. It can be excitatory or inhibitory in other areas.
Norepinephrine, a hormone, can be excitatory or inhibitory.
Dopamine is generally excitatory, yet may be inhibitory at some sites. This is recognized as a major contributor to violent tendencies in humans. High levels have been proven to make individuals more aggresive.
Seratonin is generally inhibitory and is often associated with feelings of relaxation. Individuals who are chemically imbalanced as indicated by depressive behavior often take the prescription drug Prozac, which helps to replace lacking seratonin.
Several Amino Acids and Neuropeptides make up the remaining six or more known neurotransmitters.
Introduction to Neuroscience
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