Responses of caudal vestibular nucleus neurons of conscious cats to rotations in vertical planes, before and after a bilateral vestibular neurectomy
Responses of caudal vestibular nucleus neurons of conscious cats to rotations in vertical planes, before and after a bilateral vestibular neurectomy
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DOI：
10.1007/s00221-008-1359-z
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发表时间：
2008-06-01
影响因子：
2
通讯作者：
Yates, B. J.
中科院分区：
文献类型：
--
作者：
Miller, D. M.;Cotter, L. A.;Yates, B. J.
虽然许多以前的实验已经考虑了前庭核神经元的旋转和头部的平移的反应，很少有数据是关于前庭核（CVN），介导前庭自主神经反应等功能的caudmost部分的细胞。本研究探讨了清醒猫的CVN神经元的反应，在垂直面旋转，之前和之后的双侧前庭神经切除术。数据样本中包含的单元均不具有眼动相关活动。在脊髓完整的动物，一些CVN神经元（22%）表现出重力感受性反应与耳石器官的输入一致，但大多数（55%）有动态响应与刺激速度同步的相位。此外，绝大多数的CVN神经元的响应矢量的方向，对齐或附近的滚动或垂直管平面，只有18%的细胞优先激活俯仰旋转。持续的头向上旋转的身体提供了挑战，心血管系统和呼吸，因此，绝大多数的CVN神经元的反应动力学是不同的姿势相关的自主反射。这些数据表明，前庭对CVN介导的自主控制的影响比以前设想的更复杂，可能涉及相当大的处理和整合的信号脑干区域参与心血管和呼吸调节。双侧前庭神经切除后，CVN神经元在24小时内恢复自发活动，极少数神经元（< 10%）对幅度< 15度的垂直倾斜有反应。这些研究结果表明，nonalcohine输入可能是重要的，在维持CVN神经元的活动，因此，这些输入可能发挥作用，在功能恢复后外周前庭病变。
Although many previous experiments have considered the responses of vestibular nucleus neurons to rotations and translations of the head, little data are available regarding cells in the caudalmost portions of the vestibular nuclei (CVN), which mediate vestibulo-autonomic responses among other functions. This study examined the responses of CVN neurons of conscious cats to rotations in vertical planes, both before and after a bilateral vestibular neurectomy. None of the units included in the data sample had eye movement-related activity. In labyrinth-intact animals, some CVN neurons (22%) exhibited graviceptive responses consistent with inputs from otolith organs, but most (55%) had dynamic responses with phases synchronized with stimulus velocity. Furthermore, the large majority of CVN neurons had response vector orientations that were aligned either near the roll or vertical canal planes, and only 18% of cells were preferentially activated by pitch rotations. Sustained head-up rotations of the body provide challenges to the cardiovascular system and breathing, and thus the response dynamics of the large majority of CVN neurons were dissimilar to those of posturally-related autonomic reflexes. These data suggest that vestibular influences on autonomic control mediated by the CVN are more complex than previously envisioned, and likely involve considerable processing and integration of signals by brainstem regions involved in cardiovascular and respiratory regulation. Following a bilateral vestibular neurectomy, CVN neurons regained spontaneous activity within 24 h, and a very few neurons (< 10%) responded to vertical tilts < 15 degrees in amplitude. These findings indicate that nonlabyrinthine inputs are likely important in sustaining the activity of CVN neurons; thus, these inputs may play a role in functional recovery following peripheral vestibular lesions.