activities, Chinn(1953)and Crampton and Daunton(1983)found pr tion, almost never produce inal fluid( CSF) transport is argu ur under some conditions where the ph 卿0 ven completely absent. vomiting that is observed experime时wts al body motion stimulus is norm pathways(see below) and significant interspecies differences Just as a worki beginning to emerge, other experi ng to replicate and exten the traditional attempt ckness, even though 比二 cy n ated and cerebellar iller and Wilson 1983a hensive etiologic theory was Wilpizeski et al. 1986), and workers now doubt that medullary was an as yet unidentified signal in the orientation Certainly some aspects of the physiology of the"output" nerated or not. When this intemal neural or humoral signal been experimentally defined(e. g, Miller et al. 1987). That so atory, vasomotor, and gastric responses are consis eventually producing symptoms and signs. Many worke tent signs of motion sickness indicates that areas in the reticu- undoubtedly assumed that the linkage would be easily identi- lar core of the brainstem traditionally associated with of spatial orientation and emetic pathways in the CNS were animals and people can be made motion sick, the limt better understood ortex (HPA)neuroend Physiological basis of motion sickness normally involved in mediating responses: increases in circu- nd during sick nat effective drugs stem that subserve postural simply raise the threshold for sickness. Antimotion sicknes now known to by Henn ( 1980). A brainstem 1954), which has been found to receive convergent inputs from a variety of other central and peripheral sources, includ- of th w油AM由如 not yet have: complete physiologi ctivity in this vomiting center(Money 1970). The integrity of definition of motion sickness, the development of a succession both the vomiting center and an adjacent"chem receptive of"sensory r etiologic perspective on the syndrome. The the fourth ventricle, was found to conflict theory has been widely accepted, and as a result 4: Brizzee and Neal 1954). abla- ts indicated the cerebellar nodulus and uvul tacle scones, wide-screen movie sickness, figh sta. spor somei the orientation brain ness), and the nausea and the vomiting produced by vestibu probably via the cerebellum, to the chemoreceptive trigg nd-organ disease simply as different examples of a zone, which in tum activated the vomiting center. wang and sensory conflict"related nausea and vomiting syndrom