Department of Psychology, University of Exeter, Exeter, EX4 4QC, UK; Prince of Wales Clinical School, UNSW, Sydney, NSW 2052, Australia.
Prince of Wales Clinical School, UNSW, Sydney, NSW 2052, Australia; Neuroscience Research Australia, UNSW, Sydney, NSW 2052, Australia.
Neurosci Lett. 2021 Jul 13;757:135960. doi: 10.1016/j.neulet.2021.135960. Epub 2021 May 26.
In this work we examine the possible neural basis for two brainstem-spinal reflexes using source analyses of brain activity recorded over the cortex and posterior fossa. In a sample of 5 healthy adult subjects, using axial and vestibular stimulation by means of applied impulsive forces, evoked potentials were recorded with 63 channels using a 10 % cerebellar extension montage. In parallel, EMG was recorded from soleus and tibialis anterior muscles and accelerometry from the lower leg. Recordings over the cerebellum (ECeG) confirmed the presence of short latency (SL) potentials and these were associated with changes in high-frequency power. The SL responses to the two stimulus modalities differed in that the axial stimulation produced an initial pause and then a burst in the high-frequency ECeG, followed by excitation/inhibition in soleus while vestibular stimulation produced an initial burst then a pause, followed by inhibition/excitation in soleus. These short latency responses were followed by longer latency N1/P2/N2 responses in the averaged EEG, which were maximal at FCz. Brain Electrical Source Analysis (BESA) demonstrated both cerebellar and cerebral cortical contributions to the short-latency responses and primarily frontal cortex contributions to the long-latency EPs. The latency and polarity of the SL EPs, in conjunction with changes in high-frequency spontaneous activity, are consistent with cerebellar involvement in the control of brainstem-spinal reflexes. The early involvement of frontal cortex and subsequent later activity may be an indicator of the activation of the cortical motor-related system for rapid responses which may follow the reflexive components. These findings provide evidence of the feasibility of non-invasive electrophysiology of the human cerebellum and have demonstrated cerebellar and frontal activations associated with postural-related stimuli.
在这项工作中，我们使用记录在皮质和后颅窝的脑活动的源分析来检查两个脑干-脊髓反射的可能神经基础。在 5 名健康成年受试者的样本中，使用轴向和前庭刺激通过施加脉冲力，使用 10%小脑扩展电极记录了 63 通道的诱发电位。同时，从比目鱼肌和胫骨前肌记录肌电图，并从小腿记录加速度计。对小脑（ECeG）的记录证实了短潜伏期（SL）电位的存在，并且这些电位与高频功率的变化相关。两种刺激模式的 SL 反应不同，轴向刺激产生初始暂停，然后在高频 ECeG 中产生爆发，随后在比目鱼肌中产生兴奋/抑制，而前庭刺激产生初始爆发，然后暂停，随后在比目鱼肌中产生抑制/兴奋。这些短潜伏期反应后，在平均脑电图中出现更长潜伏期的 N1/P2/N2 反应，在 FCz 处达到最大值。脑电源分析（BESA）证明了短潜伏期反应既有小脑的贡献，也有大脑皮层的贡献，而长潜伏期 EPs 主要是额叶皮层的贡献。SL EP 的潜伏期和极性，以及高频自发活动的变化，与小脑参与控制脑干-脊髓反射一致。额叶皮层的早期参与和随后的后期活动可能是皮质运动相关系统激活的指标，该系统可能会跟随反射性成分。这些发现为人类小脑非侵入性电生理学的可行性提供了证据，并证明了小脑和额叶的激活与姿势相关刺激有关。
