HABITUATION AND MOTION SICKNESS

Citation
Cd. Wood et al., HABITUATION AND MOTION SICKNESS, Journal of clinical pharmacology, 34(6), 1994, pp. 628-634
Citations number
19
Categorie Soggetti
Pharmacology & Pharmacy
ISSN journal
00912700
Volume
34
Issue
6
Year of publication
1994
Pages
628 - 634
Database
ISI
SICI code
0091-2700(1994)34:6<628:HAMS>2.0.ZU;2-L
Abstract
The vestibular, cerebellar, and reticular systems are central in impor tance, in motion sickness and habituation, to the effects of motion. N uclear medicine single photon emission computed tomography (SPECT) stu dies of cerebral blood flow and power spectral electroencephalographic recordings during motion sickness were used to determine alterations in the central nervous system. The rotating chair with and without vis ual stimulation was used to study the rate of habituation and the effe ct of antimotion sickness medications on this rate. An increase of the ta waves over the frontal cortex indicated a decreased activation of t he higher centers during motion sickness. Motion sickness also produce s an increase of blood flow in the central cerebellum that has connect ions to the reticular system. This increase in cerebellar activity is relayed to the reticular system whereby neural recruitment builds up t o trigger the vomiting center, producing motion sickness. Habituation may be a conditioned compensatory activation of the reticular neurons that prevents this disruption of normal activation. The rate of habitu ation when motion sickness was prevented by scopolamine was slowed, in dicating that, if the central nervous system is not challenged by disr uption of normal activation, it does not produce the compensatory reac tions that result in habituation.