Gastrin is the name of the neuropeptide that carries the message of fear from the amygdala to the gut. Upon arrival in the gut, gastrin gives rise to dyspepsia — those gut-wrenching feelings of 'butterflies in the stomach' that we experience as qualms, quease, anxiety, nausea, disgust, anger, biliousness or feeling galled.
Bombesin is the name of the neuropeptide that carries the message of fear from the amygdala to the periphery of the body. Upon arrival, bombesin causes a shutdown of the blood supply to the skin, wherupon our color blanches, we get goose bumps, and we feel 'chilled out' (white as a ghost). Creepy. Shiver me timbers.
Gastrin Bombesin as
Oil Can Harry A-Go-Go
AKA Mr. GutWrench