The deep layers of the superior colliculus.
The deep layers of the superior colliculus.
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发表时间：
1989
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通讯作者：
D. Sparks;R. Hartwich-Young
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文献类型：
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作者：
D. Sparks;R. Hartwich-Young
证据是令人信服的，深层的SC参与翻译的感觉信号转化为运动命令的控制扫视眼球运动。深层接收来自大脑区域的输入，这些区域参与分析用于引导定向运动的刺激（视觉、听觉和体感）。从丘神经元记录的活动模式适合于扫视的启动和方向，并且携带这些信号的神经元在地形上被组织，形成运动（扫视）空间的地图。从深层传出投射到脑干核团，与支配眼外肌的运动神经元池有直接或间接的联系。最后，深丘神经元的可逆失活严重损害了动物产生准确扫视的能力。我们对SC的解剖和功能组织的认识仍然存在重大差距。通过传入通路传递到SC的生理信号在很大程度上是未知的。对SC的内在组织了解甚少;并且在浅表和深部的神经元之间是否存在广泛的通信的问题尚未得到解决。很少有人知道的形态，位置或生理反应的主要传出通路的起源细胞的属性;和涉及解码信息的方向，速度和幅度的扫视（包含在空间和时间模式的丘细胞的神经活动）的神经回路仍然是不明的。一般来说，深丘神经元的感觉反应的定向运动的启动的贡献是未知的。没有实验证据表明，对感觉刺激作出反应的深丘神经元的活动对于在SC中观察到的运动信号的产生是必要的或足够的，并且尚未确定SC内专门参与将感觉信号翻译成运动命令的连接模式。SC中听觉、躯体感觉和视觉地图的对齐（在麻醉或瘫痪的动物中）影响了对感觉运动整合过程的思考。通常认为SC的深部包含感觉空间的地形图-即，动物周围空间中的点由位于SC中特定位置处的神经元表示。进一步假设，源自空间中相同点的来自不同模态的感觉信号激活位于该表示内的共同丘神经元库。（400字处截断摘要）
The evidence is compelling that the deep layers of the SC are involved in the translation of sensory signals into motor commands for the control of saccadic eye movements. The deep layers receive inputs from brain areas involved in the analysis of stimuli (visual, auditory and somatosensory) used to guide orienting movements. Patterns of activity recorded from collicular neurons are appropriate for the initiation and direction of saccades, and neurons carrying these signals are organized topographically, forming a map of motor (saccadic) space. Efferent projections from the deep layers are to brainstem nuclei having direct or indirect connections with motoneuron pools innervating extraocular muscles. Finally, reversible inactivation of neurons in the deep colliculus severely impairs the ability of animals to generate accurate saccades. Major gaps in our knowledge of the anatomical and functional organization of the SC remain. The physiological signals conveyed to the SC over afferent pathways are, for the most part, unknown. The intrinsic organization of the SC is poorly understood; and the question of whether or not there is extensive communication between neurons in the superficial and deep divisions has not yet been resolved. Very little is known about the morphology, location or physiological response properties of the cells of origin of the major efferent pathways; and the neural circuits involved in decoding information about the direction, velocity and amplitude of saccades (contained in the spatial and temporal pattern of neural activity of collicular cells) are still unspecified. In general, the contribution of the sensory responses of deep collicular neurons to the initiation of orienting movements is unknown. There is no experimental evidence that the activity of deep collicular neurons responsive to sensory stimuli is either necessary or sufficient for the generation of the motor signals observed in the SC, and patterns of connections within the SC specifically involved in the translation of sensory signals into motor commands have not been identified. The alignment (in anesthetized or paralysed animals) of auditory, somatosensory and visual maps in the SC has influenced thinking about the process of sensorimotor integration. It is commonly assumed that the deep division of the SC contains topographical maps of sensory space--i.e., a point in the space surrounding the animal is represented by neurons residing at a particular location in the SC. It is assumed, further, that sensory signals from different modalities originating from the same point in space activate a common pool of collicular neurons located within this representation.(ABSTRACT TRUNCATED AT 400 WORDS)