Neurotransmitters in General
Neuromodulators in General
Catecholaminergic system in Coelenterates (PubMed)
"The catecholamine present shows similarities to noradrenalin but it is not identical with noradrenalin. Contrary to known vertebrate catecholaminergic systems, neither a reuptake system nor a degrading system is present in the coelenterate catecholaminergic nervous system."
Biogenic Amines in Coelenterates (PubMed)
"Dopamine is used as an intercellular messenger in hydrozoans. The colonian anthozoan Renilla, has beta-adrenergic mechanisms in monitoring bioluminescence and serotoninergic mechanisms in rhythmic contractions."