Reynolds J S, Blum D, Gdowski G T
Department of Biomedical Engineering and Neurobiology and Anatomy, University of Rochester, 601 Elmwood Ave., Box 603, Rochester, NY 14642, USA.
J Neurophysiol. 2008 Jun;99(6):3123-35. doi: 10.1152/jn.00793.2007. Epub 2008 Apr 24.
A major goal of this study was to characterize the cervicocollic reflexes (CCRs) in awake squirrel monkeys and compare it to observations in cat. This was carried out by stabilizing the head in space while rotating the lower body. The magnitude and phase of the torque produced between the head and the restraint system was used as an indicator of the CCR. Many properties of the squirrel monkey's CCR were found to be similar to those of the cat. The torque decreased as a function of frequency and amplitude. In addition, the static level of torque increased with head eccentricity. One difference was that the torque was 90x smaller in squirrel monkeys. Biomechanical differences, such as differences in head inertia, could account for these differences. The second goal was to determine if the CCR was sensitive to increases in the head's inertia. To test this, we increased the head's inertia by a factor of 36 and allowed the reflexes to adapt by rotating the whole body while the head was free to move. The CCR was rapidly assessed by periodically stabilizing the head in space during whole-body rotations. The magnitude of the torque increased by nearly 60%, suggesting that the CCR may adapt when changes in the head's inertia are imposed. Changes in the torque were also consistent with changes in head-movement kinematics during whole-body rotation. This suggests that the collic reflexes may dynamically adapt to maintain the performance and kinematics of reflexive head movement.
本研究的一个主要目标是描绘清醒松鼠猴的颈-颈反射（CCR），并将其与猫的观察结果进行比较。这是通过在旋转下半身时稳定头部在空间中的位置来实现的。头部与约束系统之间产生的扭矩的大小和相位被用作CCR的指标。发现松鼠猴的CCR的许多特性与猫的相似。扭矩随频率和幅度的函数而减小。此外，扭矩的静态水平随头部偏心率增加。一个不同之处在于松鼠猴的扭矩小90倍。生物力学差异，如头部惯性的差异，可以解释这些差异。第二个目标是确定CCR是否对头部惯性的增加敏感。为了测试这一点，我们将头部惯性增加了36倍，并在头部自由移动时通过旋转整个身体使反射适应。在全身旋转过程中，通过定期在空间中稳定头部来快速评估CCR。扭矩的大小增加了近60%，这表明当头部惯性发生变化时，CCR可能会适应。扭矩的变化也与全身旋转过程中头部运动学的变化一致。这表明脑桥反射可能会动态适应，以维持反射性头部运动的性能和运动学。
