A theory of motion sickness based on pharmacological reactions

Abstract

A series of anti‐motion sickness drug evaluation experiments has been performed at the Naval Aerospace Medical Institute in Pensacola. Carefully controlled laboratory conditions using the slow‐rotation room were maintained. The results were confirmed by similar experiments in the air and at sea. The effective drugs fell into two categories, those that blocked acetylcholine in the central nervous system and those which activated the central sympathetic areas. A combination of drugs involving both of these mechanisms was the most effective preparation for preventing motion sickness. These results have indicated that there may be competitive neural systems involved with motion sickness, one activated by acetylcholine and one most likely mediated by norepinephrine. Motion sickness would occur when activation of the acetylcholine system disturbed this balance, and protection of the motion sickness drugs would be achieved by preventing it.