
(from the article `endocrine system, human`) ...A large number of additional neurotransmitters have been discovered, of which an important group is the neuropeptides. The neuropeptides function ... Further complicating neurotransmitter action is the presence not only of multiple transmitter substances but also of neuromodulators. Neurom...
Found on
http://www.britannica.com/eb/a-z/n/29

Any substance that modifies or modulates the activities of the postsynaptic neuron.
Found on
https://www.encyclo.co.uk/local/22842

any of various substances, as certain hormones and amino acids, that influence the function of neurons but do not act as neurotransmitters.
Found on
https://www.infoplease.com/dictionary/neuromodulator
No exact match found.