May act as a neurotransmitter or neuromodulator and play a role in the integration of information within the brain. May be involved in the control of visceral muscles due to its ability to behave as potent inhibitors of peristaltic movements. May also fulfill a neurohormonal role on muscles of the gut and heart. Brain, subesophageal ganglion, retrocerebral complex, thoracico-abdominal ganglion, peripheral neurosecretory system and intestine. Belongs to the allatostatin family.