premise: Dopamine causes neuromodulation.
hypothesis: Dopamine . In the brain , dopamine functions as a neurotransmitter -- a chemical released by neurons ( nerve cells ) to send signals to other nerve cells . These pathways and cell groups form a dopamine system which is neuromodulatory . Neuromodulation is the physiological process by which a given neuron uses one or more chemicals to regulate diverse populations of neurons . Major neuromodulators in the central nervous system include dopamine , serotonin , acetylcholine , histamine , and norepinephrine . In both cases the transmitter acts on local postsynaptic receptors , but in neuromodulation , the receptors are typically G-protein coupled receptors while in classical chemical neurotransmission , they are ligand-gated ion channels .