one of a number of endogenous peptides which function as selective agonists for the delta-opioid receptors.
Involved in pain and pleasure, the peptide neurotransmitter is part of the endogenous morphine system.
a chemical substance produced by the brain which acts as an opiate and produces analgesia to increase the threshold for pain.
Peptide neurotransmitter at some synapses activated by opiate drugs; an endogenous opioid.
a kind of neurotransmitter, known as a neuropeptide, which serves in particular regions of the brain