Observation on the response of rats and human to motion sickness stimulated by vertical motion on simulated ship / 解放军医学杂志

ABSTRACT

Objective To observe the pathogenesis of motion sickness with different frequencies and accelerations of heave motion. Methods Sixty-four adult male healthy rats were randomly divided into four groups (n=16) Vertical motion mode A (frequency 0.20 Hz, acceleration 0.05 g), vertical motion mode B (frequency 0.40 Hz, acceleration 0.13 g), vertical motion mode C (frequency 0.80 Hz, acceleration 0.48 g) and static control group. The severity of motion sickness was evaluated by three indicators Frequency of conditioned gaping (nausea like reaction), number of defecation particles and spontaneous activity. Thirty-six male healthy volunteers were randomly divided into four groups (n=9) Vertical motion mode I (frequency 0.42 Hz, acceleration 0.22 g), vertical motion mode II (frequency 0.42 Hz, acceleration 0.44 g), vertical motion mode III (frequency 0.30 Hz, acceleration 0.33 g), and vertical motion mode IV (frequency 0.25 Hz, acceleration 0.44 g). A modified version of motion-sickness susceptibility questionnaire (MSSQ) was used to evaluate the susceptibility to motion sickness before the test, and Graybiel motion sickness scale to evaluate the severity of motion sickness during the test. MATLAB software was used to establish a population test mathematical model and draw a trend chart. ResultsCompared with the static control group, rats receiving mode A stimulation did not show significant symptoms of motion sickness, and both the number of conditioned gaping and the number of defecation particles in the vertical motion group B and the vertical motion group C significantly increased, while the spontaneous locomotion activity was significantly reduced after the motion sickness stimulation (P<0.05 or P<0.001). Symptoms became more obvious as the frequency of stimulation increases. Besides, the results of the crowd test indicated that after receiving different stimulations of modes I, II, III and IV, the Graybiel scores were 7.67±6.36, 4.22±4.97, 1.44±1.51, 0.22±0.44 respectively, with the highest incidence of nausea in the vertical motion group I. MATLAB software analysis shows that as the stimulus frequency increases, the score of motion sickness increases, while when the frequency was fixed, Graybiel score increased first and then decreased as the acceleration increased. ConclusionThe occurrence rules of simulated seasickness in rats and human under the stimulation of vertical motion have been preliminarily clarified, which could provide an experimental basis for anti-seasickness simulation training.