Biogenic amine neurotransmitters in C.

Four biogenic amines: octopamine, tyramine, dopamine and serotonin act in C. elegans to modulate behavior in response to changing environmental cues. These neurotransmitters act at both neurons and muscles to affect egg laying, pharyngeal pumping, locomotion and learning. A variety of experimental approaches including genetic, imaging, biochemical and pharmacological analyses have been used to identify the enzymes and cells that make and release the amines and the cells and receptors that bind them. Dopamine and serotonin act through receptors and downstream signaling mechanisms similar to those that operate in the mammalian brain suggesting that C. elegans will provide a valuable model for understanding biogenic amine signaling in the brain.