neurotransmitter

n. inter-neural chemical conductor, chemical carrier of information throughout the nervous system (Neurology)

Neurotransmitters are chemicals that are used to relay, amplify and modulate signals between a neuron and another cell. According to the prevailing beliefs of the 1960s, a chemical can be classified as a neurotransmitter if it meets the following conditions:It is synthesized endogenously, that is, within the presynaptic neuron;It is available in sufficient quantity in the presynaptic neuron to exert an effect on the postsynaptic neuron;Externally administered, it must mimic the endogenously-released substance; andA biochemical mechanism for inactivation must be present.
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Noun
1. transmits nerve impulses across a synapse
(hypernym) neurochemical
(hyponym) epinephrine, epinephrin, adrenaline, Adrenalin

n. neurotransmitter, inter-neural chemical conductor, chemical carrier of information throughout the nervous system (Neurology)

Any of more than 200 chemicals that are stored in nerve cells and convey signals from one nerve cell to a proximate nerve cell or muscle cell.