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n. A chemical substance, such as acetylcholine or dopamine, that transmits nerve impulses across a synapse.

n. Any substance, such as acetylcholine or dopamine, responsible for sending nerve signals across a synapse between two neurons.

n. a neurochemical that transmits nerve impulses across a synapse

"To give you a little bit of background (if you want more, see the post on dopamine), dopamine is a signaling molecule known as a neurotransmitter, which is released from one neuron and binds to receptors on another neuron to produce effects."

neurochemical   

serotonin    norepinephrine    dopamine    acetylcholine    adenosine triphosphate   

epinephrine    acetylcholine    gamma aminobutyric acid    GABA    adrenaline   

norepinephrine    noradrenaline    neurotransmitters    melatonin    glutamate