Cerebellar lesions and prism adaptation in Macaque monkeys
Cerebellar lesions and prism adaptation in Macaque monkeys
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DOI：
10.1152/jn.1999.81.4.1960
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发表时间：
1999-04-01
影响因子：
2.5
通讯作者：
Glickstein, M
中科院分区：
文献类型：
--
作者：
Baizer, JS;Kralj-Hans, I;Glickstein, M
如果将一个使光线横向偏移的棱镜放在人或猴子的一只眼前，同时遮住另一只眼，它们最初会指向正前方目标的一侧。通常，人和猴子很容易适应这种偏移的视觉，经过几次尝试后就能纠正他们的瞄准方向。如果随后移除棱镜，会出现一种适应后偏移现象，即受试对象会在几次尝试中错过目标并指向相反方向。我们测试了五只猕猴适应横向偏移棱镜以及表现出预期的适应后偏移的能力。在正常测试时，所有五只动物都表现出典型的适应和适应后偏移模式。和人类受试对象一样，猴子也表现出适应的完全眼间转移，但在两只手臂之间没有适应转移。当术前训练和测试完成后，我们对小脑皮质的各个目标区域造成损伤。在五只猴子中的一只猴子身上，一个包括背侧副绒球和小脑蚓垂的小脑损伤完全消除了损伤同侧手臂对棱镜的正常适应。其他四只动物保留了正常适应棱镜的能力，并表现出预期的适应后偏移。在损伤消除棱镜适应的这一个案例中，损伤包括小脑半球的 Crus I和II、旁正中小叶和背侧副绒球，以及小脑蚓部的小叶LY。因此，在这个案例中，损伤几乎包括了所有通过脑桥核从中枢皮质中继接收苔藓纤维视觉信息的小脑皮质。其他四只动物的小叶V（经典的前叶手臂区域）和/或小脑蚓部的小叶VI/VII（动眼神经区域）受到损伤。在术后测试时，其中一些动物表现出一定程度的共济失调，其程度与棱镜适应受影响的案例相当，但棱镜适应和适应后偏移仍然正常。我们得出结论，除了在长期运动学习和反射适应中的作用外，被切除的小脑区域可能也是短期运动记忆的关键部位。棱镜适应似乎涉及小脑的一个区域，该区域接收苔藓纤维视觉误差信号，可能还接收运动的伴随放电。
If a laterally displacing prism is placed in front of one eye of a person or monkey with the other eye occluded, they initially will point to one side of a target that is located directly in front of them. Normally, people and monkeys adapt easily to the displaced vision and correct their aim after a few trials. If the prism then is removed, there is a postadaptation shift in which the subject misses the target and points in the opposite direction for a few trials. We tested five Macaque monkeys for their ability to adapt to a laterally displacing prism and to show the expected postadaptation shift. When tested as normals, all five animals showed the typical pattern of adaptation and postadaptation shift. Like human subjects, the monkeys also showed complete interocular transfer of the adaptation but no transfer of the adaptation between the two arms. When properative training and testing was complete, we made lesions of various target areas on the cerebellar cortex. A cerebellar lesion that included the dorsal paraflocculus and uvula abolished completely the normal prism adaptation for the arm ipsilateral to the lesion in one of the five monkeys. The other four animals retained the ability to prism-adapt normally and showed the expected postadaptation shift. In the one case in which the lesion abolished prism adaptation. the damage included Crus I and II, paramedian lobule and the dorsal paraflocculus of the cerebellar hemispheres as will as lobule LY, of the vermis. Thus in this case, the lesion included virtually all the cerebellar cortex that receives mossy-fiber visual information relayed via the pontine nuclei from the cerebral cortex. The other four animals had damage to lobule V, the classical anterior lobe arm area and/or vermian lobules VI/VII, the oculomotor region. When tested postoperatively, some of those animals showed a degree of ataxia equivalent to that of the case in which prism adaptation was affected, but prism adaptation and the postadaptation shift remained normal. We conclude that in addition to its role in long-term motor learning and reflex adaptation, the region of the cerebellum that was ablated also may be a critical site for a short-term motor memory. Prism adaptation seems to involve a region of the cerebellum that receives a mossy-fiber visual error signal and probably a corollary discharge of the movement.