A G protein-coupled receptor signaling pathway initiated by octopamine or tyramine binding to their receptor on the surface of a target cell, and ending with the regulation of a downstream cellular process, e.g. transcription, and ending with the regulation of a downstream cellular process. Octopamine and tyramine are decarboxylation products of tyrosine, and are the invertebrate counterparts of the vertebrate adrenergic transmitters.
octopamine or tyramine signalling pathway