Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA.
J Neurosci. 2012 Sep 19;32(38):13237-43. doi: 10.1523/JNEUROSCI.2595-12.2012.
Accumulating evidence shows that the oculomotor plant is capable of implementing aspects of three-dimensional kinematics such as Listing's law and the half-angle rule. But these studies have only examined the eye under static conditions or with movements that normally obey these rules (e.g., saccades and pursuit). Here we test the capability of the oculomotor plant to rearrange itself as necessary for non-half-angle behavior. Three monkeys (Macaca mulatta) fixated five vertically displaced targets along the midsagittal plane while sitting on a motion platform that rotated sinusoidally about the naso-occipital axis. This activated the torsional, rotational vestibulo-ocular reflex, which exhibits a zero-angle or negative-angle rule (depending on the visual stimulus). On random sinusoidal cycles, we stimulated the abducens nerve and observed the resultant eye movements. If the plant has rearranged itself to implement this non-half-angle behavior, then stimulation should reveal this behavior. On the other hand, if the plant is only capable of half-angle behavior, then stimulation should reveal a half-angle rule. We find the latter to be true and therefore additional neural signals are likely necessary to implement non-half-angle behavior.
越来越多的证据表明，眼动植物具有实施三维运动学的各个方面的能力，例如 Listing 法则和半角法则。但这些研究仅在静态条件下或在通常遵循这些规则的运动（例如扫视和追踪）下检查了眼睛。在这里，我们测试了眼动植物根据需要重新排列自身以适应非半角行为的能力。三只猴子（Macaca mulatta）坐在运动平台上，该平台绕额枕轴以正弦波方式旋转，同时固定在中矢状面的五个垂直偏移目标上。这激活了扭转、旋转前庭眼反射，该反射表现出零角或负角法则（取决于视觉刺激）。在随机正弦周期中，我们刺激外展神经并观察到由此产生的眼球运动。如果植物已经重新排列自身以实施这种非半角行为，则刺激应该揭示这种行为。另一方面，如果植物只能进行半角行为，那么刺激应该揭示半角法则。我们发现事实确实如此，因此可能需要额外的神经信号来实施非半角行为。
