Does the middle temporal area carry vestibular signals related to self-motion?
Does the middle temporal area carry vestibular signals related to self-motion?
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DOI：
10.1523/jneurosci.0004-09.2009
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发表时间：
2009-09-23
期刊：
影响因子：
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通讯作者：
Angelaki DE
中科院分区：
文献类型：
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作者：
Chowdhury SA;Takahashi K;DeAngelis GC;Angelaki DE
最近的研究描述了背侧内侧上颞区（MSTd）的前庭反应，该区域是纹状视觉皮层的区域，被认为与自我运动感知有关。目前尚不清楚前庭信号传递到 MSTd 区域的途径，一种可能性是前庭信号已经存在于已知为 MSTd 提供视觉输入的区域中。因此，我们检查了中颞区 (MT) 中的单个神经元是否表现出选择性前庭反应，中颞区是一个视觉运动敏感区域，主要投射到 MSTd 区域。我们比较了 MT 和 MSTd 对 3D 旋转和平移刺激的反应，这些刺激要么使用运动平台（前庭条件）呈现，要么使用光流（视觉条件）模拟。当猴子注视投影仪产生的视觉目标时，一半的 MT 细胞（以及大多数 MSTd 神经元）在前庭旋转条件下表现出显着的调节。然而，当在暗室中用激光产生固定目标时，大多数 MT 神经元失去了前庭调谐，而大多数 MSTd 神经元保留了选择性。在黑暗中自由观看也获得了类似的结果。我们的研究结果表明，MT 神经元并未表现出对自我运动的真正前庭反应；相反，它们在前庭旋转条件下的调节可以通过残余前庭眼反射引起的视网膜滑动来解释。因此，在 MSTd 区域观察到的稳健前庭信号并不是通过 MT 区域的输入产生的。
Recent studies have described vestibular responses in the dorsal medial superior temporal area (MSTd), a region of extrastriate visual cortex thought to be involved in self-motion perception. The pathways by which vestibular signals are conveyed to area MSTd are currently unclear, and one possibility is that vestibular signals are already present in areas that are known to provide visual inputs to MSTd. Thus, we examined whether selective vestibular responses are exhibited by single neurons in the middle temporal area (MT), a visual motion-sensitive region that projects heavily to area MSTd. We compared responses in MT and MSTd to 3D rotational and translational stimuli that were either presented using a motion platform (vestibular condition) or simulated using optic flow (visual condition). When monkeys fixated a visual target generated by a projector, half of MT cells (and most MSTd neurons) showed significant tuning during the vestibular rotation condition. However, when the fixation target was generated by a laser in a dark room, most MT neurons lost their vestibular tuning whereas most MSTd neurons retained their selectivity. Similar results were obtained for free viewing in darkness. Our findings indicate that MT neurons do not show genuine vestibular responses to self-motion; rather, their tuning in the vestibular rotation condition can be explained by retinal slip due to a residual vestibulo-ocular reflex. Thus, the robust vestibular signals observed in area MSTd do not arise through inputs from area MT.