Angelaki D E, Hess B J, Suzuki J
Department of Surgery (Otolaryngology), University of Mississippi Medical Center, Jackson 39216-4505, USA.
J Neurosci. 1995 Nov;15(11):7201-16. doi: 10.1523/JNEUROSCI.15-11-07201.1995.
Selective semicircular canal inactivation and three-dimensional eye movement recordings have been used to investigate the spatial organization of vestibular signals in the vestibulo-ocular reflex (VOR) of rhesus monkeys. In animals with one pair of semicircular canals inactivated, afferent activity no longer codes all spatial components of head angular velocity. if it were the activation pattern of semicircular canal afferents alone that determines VOR slow phase eye velocity, the head velocity components along the sensitivity vectors of the remaining intact semicircular canals would determine the orientation of slow phase eye velocity. Thus, angular head velocity and slow phase eye velocity would not necessarily always align. Alternatively, if vestibulo-ocular signals coded absolute angular head motion in space based on both semicircular canal and otolith afferent information, one might expect a spatial transformation of the encoded head angular velocity signals such that slow phase eye velocity and angular head velocity continue to spatially align. Examination of the VOR at different frequencies between 0.01 Hz and 1 Hz revealed a frequency-specific spatial organization of vestibulo-ocular signals. Mid and high frequency vestibulo-ocular responses were determined exclusively by the orientation of the sensitivity vectors of the remaining intact semicircular canals. In contrasts, low frequency vestibulo-ocular responses were largely determined by the orientation of the head relative to gravity. These low frequency responses after selective semicircular canal inactivation could be predicted and simulated by a simple model where semicircular canal signals are spatially transformed from a head-fixed to a space-fixed (inertial) representation of angular head velocity. These findings suggest that low frequency vestibulo-ocular responses are dominated by inertial vestibular signals that detect absolute head motion in space based on both semicircular canal and otolith afferent information. Inertial vestibular signals are likely to contribute to head control and motor coordination of gaze, head and body posture.
选择性半规管失活和三维眼动记录已被用于研究恒河猴前庭眼反射（VOR）中前庭信号的空间组织。在一对半规管失活的动物中，传入活动不再编码头部角速度的所有空间成分。如果仅由半规管传入神经的激活模式决定VOR慢相眼速度，那么沿着其余完整半规管敏感矢量的头部速度成分将决定慢相眼速度的方向。因此，头部角速度和慢相眼速度不一定总是对齐的。或者，如果前庭眼信号基于半规管和耳石传入信息编码空间中的绝对头部角运动，那么可能会预期编码的头部角速度信号会发生空间转换，使得慢相眼速度和头部角速度在空间上继续对齐。在0.01 Hz至1 Hz的不同频率下检查VOR，发现前庭眼信号具有频率特异性的空间组织。中高频前庭眼反应完全由其余完整半规管敏感矢量的方向决定。相比之下，低频前庭眼反应在很大程度上由头部相对于重力的方向决定。选择性半规管失活后的这些低频反应可以通过一个简单的模型进行预测和模拟，在该模型中，半规管信号从头部固定的角头速度表示在空间上转换为空间固定（惯性）表示。这些发现表明，低频前庭眼反应主要由惯性前庭信号主导，这些信号基于半规管和耳石传入信息检测空间中的绝对头部运动。惯性前庭信号可能有助于头部控制以及注视、头部和身体姿势的运动协调。
