Bypassing the Saccadic Pulse Generator: Possible Control of Head Movement Trajectory by Rat Superior Colliculus
Bypassing the Saccadic Pulse Generator: Possible Control of Head Movement Trajectory by Rat Superior Colliculus
复制标题
绕过扫视脉冲发生器：大鼠上丘对头部运动轨迹的可能控制
DOI：
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发表时间：
1991
影响因子：
3.4
通讯作者：
P. Redgrave
中科院分区：
文献类型：
--
作者：
S. M. King;P. Dean;P. Redgrave
灵长类动物的上级丘的电刺激所产生的扫视主要受刺激电极的位置的影响，刺激脉冲串的阈上强度或频率几乎没有影响。任何给定的丘部位都产生一种幅度和速度相对固定的特征性运动。根据这一发现，在扫视眼球运动系统的模型中，上级丘指定了眼球位置的变化：运动分量的速度由位于上级丘和眼神经元之间的“脉冲发生器”确定。然而，先前在啮齿动物中的发现表明，在某些丘部位刺激诱导的眼睛和头部运动可能严重依赖于刺激参数，这意味着在这些动物中，上级丘可以访问非扫视控制系统。为了研究这种可能性，研究人员用不同频率和持续时间的脉冲串刺激大鼠，并从录像带中分析由此产生的头部运动。在研究的9个部位中的7个部位，头部运动水平分量的振幅与固定持续时间训练的刺激频率线性相关，在某些情况下超过10倍范围。随后的列车持续时间的变化表明，幅度的影响，而不是由频率本身，但在列车中的脉冲数;频率与运动的平均速度。通过对这些参数的适当设置，可以实现头部运动幅度和速度的独立控制。这些结果表明，啮齿类动物的上级丘可能能够控制头部运动，而无需求助于脉冲发生器，从而直接影响运动的轨迹。如果是这样的话，它可能被证明是一个有用的准备测试理论的弹道形成。
Saccades produced by electrical stimulation of the superior colliculus in primates are influenced primarily by the location of the stimulating electrode, with the suprathreshold intensity or frequency of the stimulating pulse train having little effect. Any given collicular site produces a characteristic movement of relatively fixed amplitude and velocity. In accordance with this finding, in models of the saccadic eye movement system the superior colliculus specifies the change of eye position: the velocity of movement components are determined by ‘pulse generators’ located between the superior colliculus and the oculomotor neurons. Previous findings in rodents, however, have suggested that eye and head movements induced by stimulation at some collicular sites may be critically dependent on stimulation parameters, implying that in these animals the superior colliculus has access to a non‐saccadic control system. To investigate this possibility, rats with electrodes implanted into the lateral intermediate layers were stimulated with pulse trains of varying frequency and duration, and the resultant head movements analysed from video tape. At seven of the nine sites studied, amplitude of the horizontal component of the head movement was linearly related to stimulating frequency for fixed‐duration trains, in some cases over a ten‐fold range. Subsequent variation of train duration showed that amplitude was affected not by frequency as such, but by the number of pulses in the train; frequency was related to the mean velocity of the movement. By appropriate setting of these parameters, independent control of head movement amplitude and velocity could be achieved. These results suggest that the rodent superior colliculus may be able to control head movement without recourse to a pulse generator, and thus influence the trajectory of the movement directly. If so, it may prove to be a useful preparation for testing theories of trajectory formation.
影响因子：
13.9
作者：
Sparks,DL;Mays,LE
通讯作者：
Mays,LE
DOI：
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发表时间：
1989
期刊：
Reviews of oculomotor research
影响因子：
--
作者：
D. Sparks;R. Hartwich-Young
通讯作者：
D. Sparks;R. Hartwich-Young