Facultad de Medicina, Universidad Autónoma del Estado de México, Toluca de Lerdo, México.
Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, Puebla, México.
Eur J Neurosci. 2021 Jul;54(2):4670-4681. doi: 10.1111/ejn.15338. Epub 2021 Jun 22.
The study of cardiovascular function with galvanic vestibular stimulation has provided evidence on the neural structures that are involved in the vestibulo-autonomic reflex. This study determined if the effect on heart rate using galvanic vestibular stimulation persists after provoking a sympathetic response and if this response differs when using unilateral or transmastoid (bilateral) stimulation. We analysed heart rate and heart rate variability using unilateral and transmastoid galvanic vestibular stimulation combined with cardiovascular reflex evoked by postural change in 24 healthy human subjects. Three electrode configurations were selected for unilateral stimulation considering the anatomical location of each semicircular canal. We compared recordings performed in seated and standing positions, and with unilateral and transmastoid stimulation. With subjects seated, a significant transient decrease in heart rate was observed with unilateral stimulation. With transmastoid stimulation, heart rate decreased in both seated and standing positions. Average intervals between normal heartbeats recorded with stimulation resemble parasympathetic cardiac function induced by auricular vagal nerve stimulation. Our results indicate that unilateral stimulation does not eliminate the natural heart rate increase caused by orthostatic hypotension. In contrast, transmastoid stimulation provoked a transient reduction in heart rate, even when subjects were standing. These responses should be considered while performing experiments with galvanic vestibular stimulation and subsequent effects in cardiac regulation mechanisms.
用电刺激前庭功能的研究为参与前庭自主反射的神经结构提供了证据。本研究旨在确定用电刺激前庭刺激心率的影响是否在引发交感神经反应后仍然存在，以及在使用单侧或经乳突（双侧）刺激时这种反应是否不同。我们分析了 24 名健康人体受试者在体位变化诱发心血管反射时，单侧和经乳突电刺激对心率和心率变异性的影响。考虑到每个半规管的解剖位置，我们选择了三种电极配置用于单侧刺激。我们比较了在坐姿和站姿以及单侧和经乳突刺激下的记录。在受试者坐姿时，单侧刺激观察到心率明显短暂下降。经乳突刺激时，在坐姿和站姿下心率均下降。刺激时记录的正常心跳之间的平均间隔与耳迷走神经刺激引起的副交感心脏功能相似。我们的结果表明，单侧刺激并不能消除由直立性低血压引起的自然心率增加。相比之下，即使受试者站立时，经乳突刺激也会引起心率短暂下降。在进行电刺激前庭刺激实验及其对心脏调节机制后续影响的实验时，应考虑这些反应。
