| Summary: | 碩士 === 國防醫學院 === 航太醫學研究所 === 87 ===
Electrophysiological studies in animals have reported that vestibular inputs were connected with the neurons, controlling blood pressure and heart rate in the brain stem. However, different modalities of stimulation to the vestibule may induce various cardiovascular changes in human studies. Thus, the role of vestibular inputs in modulating the cardiovascular system was still controversial. We, therefore, hypothesized that the high frequency of semicircular canal stimulation will induce elevation of blood pressure, stimulation of the otolithic organ will induce depression of blood pressure and combined both stimulations will not induce any change of blood pressure and heart rate. There are fifteen healthy volunteers in this experiment. We measure the skin blood flow, blood pressure, heart rate, electrooculogram and electrocardiogram before and after vestibulo-oculomotor stimulation. By using the human-loaded rotating plate, we study the cardiovascular responses to the rotation of different vectors (yaw, pitch, roll), frequencies (0.125, 0.25, 0.5Hz), combined vectors (yaw & pitch, pitch & roll, yaw & roll) and stimulations of the visual-vestibular sensory mismatch (yaw, roll, pitch with mismatch light rotation) for 3 min. The results show: 1). The low frequencies (0.125 and 0.25 Hz) of yaw plane pulsation stimulation do not evoke any cardiovascular response. The high frequency (0.5Hz) of yaw plane oscillation stimulation does not change the cardiovascular system either. However, the high frequency (0.5Hz) of yaw plane pulsation stimulation significantly increases the diastolic blood pressure from 72.6□2.3 to76.2□2.3 mmHg (p<0.05). 2).The low frequency (0.125 Hz) of different vector rotations, combined vector rotations and stimulations of the visual-vestibular sensory mismatch do not have any significant cardiovascular response. We conclude that vestibulo-oculomotor stimulation can generate a pressor cardiovascular response during high frequency, yaw plane and pulsation rotation but not during low frequency or oscillation rotation. The stimulations of combined vectors and visual-vestibular sensory mismatch do not produce any synergic or inhibiory cardiovascular responses, compared to responses of the single vector stimulation.
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