Siebold C, Glonti L, Glasauer S, Büttner U
Department of Neurology, Ludwig Maximilians University, Munich, Germany.
J Neurophysiol. 1997 Mar;77(3):1432-46. doi: 10.1152/jn.1997.77.3.1432.
The fastigial nucleus (FN) receives vestibular information predominantly from Purkinje cells of the vermis. FN in the monkey can be divided in a rostral part, related to spinal mechanisms, and a caudal part with oculomotor functions. To understand the role of FN during movements in space, single-unit activity in alert monkeys was recorded during passive three-dimensional head movements from rostral FN. Seated monkeys were rotated sinusoidally around a horizontal earth-fixed axis (vertical stimulation) at different orientations 15 degrees apart (including roll, pitch, vertical canal plane and intermediate planes). In addition, sinusoidal rotations around an earth-vertical axis (yaw stimulus) included different roll and pitch positions (+/-10 degrees, +/-20 degrees). The latter positions were also used for static stimulation. One hundred fifty-eight neurons in two monkeys were modulated during the sinusoidal vertical search stimulation. The vast majority showed a uniform response pattern: a maximum at a specific head orientation (response vector orientation) and a null response 90 degrees apart. Detailed analysis was obtained from 111 neurons. On the basis of their phase relation during dynamic stimulation and their response to static tilt, these neurons were classified as vertical semicircular canal related (n = 79, 71.2%) or otolith related (n = 25; 22.5%). Only seven neurons did not follow the usual response pattern and were classified as complex neurons. For the vertical canal-related neurons (n = 79) all eight major response vector orientations (ipsilateral or contralateral anterior canal, posterior canal, roll, and nose-down and nose-up pitch) were found in Fn on one side. Neurons with ipsilateral orientations were more numerous and on average more sensitive than those with contralateral orientations. Twenty-eight percent of the vertical canal-related neurons also responded to horizontal canal stimulation. None of the vertical canal-related neurons responded to static tilt. Otolith-related neurons (n = 25) had a phase relation close to head position and were considerably less numerous than canal-related neurons. Except for pitch, all other response vector orientations were found. Seventy percent of these neurons responding during dynamic stimulation also responded during static tilt. The sensitivity during dynamic stimulation was always higher than during static stimulation. Sixty-one percent of the otolith-related neurons responded also to horizontal canal stimulation. These results show that in FN, robust vestibular signals are abundant. Canal-related responses are much more common than otolith-related responses. Although for many canal neurons the responses can be related to single canal planes, convergence between vertical canals but also with horizontal canals is common.
顶核（FN）主要从前庭蚓部的浦肯野细胞接收前庭信息。猴子的顶核可分为与脊髓机制相关的前部和具有动眼功能的后部。为了解顶核在空间运动中的作用，在清醒猴子被动进行三维头部运动期间，记录了前部顶核的单单位活动。让坐着的猴子围绕水平地固定轴进行正弦旋转（垂直刺激），旋转方向相隔15度（包括翻滚、俯仰、垂直半规管平面和中间平面）。此外，围绕地垂直轴的正弦旋转（偏航刺激）包括不同的翻滚和俯仰位置（±10度，±20度）。后一种位置也用于静态刺激。在正弦垂直搜索刺激期间，两只猴子中的158个神经元受到调制。绝大多数神经元呈现出均匀的反应模式：在特定头部方向（反应向量方向）有一个反应，且在相隔90度处有一个零反应。对111个神经元进行了详细分析。根据它们在动态刺激期间的相位关系以及对静态倾斜的反应，这些神经元被分类为与垂直半规管相关（n = 79，71.2%）或与耳石相关（n = 25；22.5%）。只有7个神经元未遵循通常的反应模式，被分类为复杂神经元。对于与垂直半规管相关的神经元（n = 79），在一侧的顶核中发现了所有八个主要反应向量方向（同侧或对侧前半规管、后半规管、翻滚以及鼻下和鼻上俯仰）。同侧方向的神经元比那些对侧方向的神经元数量更多且平均更敏感。28%的与垂直半规管相关的神经元也对水平半规管刺激有反应。没有一个与垂直半规管相关的神经元对静态倾斜有反应。与耳石相关的神经元（n = 25）具有与头部位置接近的相位关系，并且数量比与半规管相关的神经元少得多。除了俯仰外，发现了所有其他反应向量方向。这些在动态刺激期间有反应的神经元中，70%在静态倾斜期间也有反应。动态刺激期间的敏感性总是高于静态刺激期间。61%的与耳石相关的神经元也对水平半规管刺激有反应。这些结果表明，在顶核中，丰富的前庭信号很充足。与半规管相关的反应比与耳石相关的反应更为常见。虽然对于许多半规管神经元来说，其反应可能与单个半规管平面有关，但垂直半规管之间以及与水平半规管之间的汇聚很常见。
