The PVN, through its vasopressinergic efferent influence on neurones in the VN we supposed, might thus play an important role in the autonomic responses to motion sickness-provoking stimuli, or alternatively, AVP, acting as an etiologic hormone in motion sickness [5, 8] through its humoral modulation on neurones in the VN, might influence the development of motion sickness. The gene discussed is AVP; the disease is motion sickness.