PONS IN CONTROL OF SACCADE GENERATION

控制眼跳生成的 PON

• 批准号: 6116295
• 负责人: ALBERT Frederick FUCHS
• 金额: $ 8.67万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2000-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6116295
• 关键词: Mammalia; Primates; nervous system; psychology

The staging area for commands that drive motoneurons, which move the eyes, resides in the pontine and medullary reticular formations of the brainstem. When the head is prevented from turning, rapid eye movements, called saccades, shift the direction of gaze with the help of brainstem neurons that discharge a burst of action potentials. These burst neurons are held in check by inhibition from neurons that usually fire steadily but cease firing or pause with all saccades. During the past year we investigated whether, when the head is free to turn and a gaze shift is composed of an eye and a head movement, the pause of these omnipause neurons (OPNs) is still best correlated with eye movement or instead controls head duration or the duration of the overall gaze shift, i.e., eye position + head position. We found that pause duration was poorly correlated with head duration. Moreover, by correlating pause duration with movement duration, we could not ascertain whether pause duration was better correlated with eye or overall gaze duration. However, when we aligned the end of the pause with the end of the saccade, the pause was almost always better aligned with the end of the eye movement than the end of the gaze movement. Therefore, we conclude that the OPNs, which lie in the pons, are involved with the eye component of a gaze shift and not with the overall gaze shift nor the head movement component. In contrast, the firing patterns of various of the aforementioned burst neurons may be better correlated with either the eye movement, the gaze movement, or the overall gaze shift. Pause and burst neurons with these characteristics fit nicely into our model for a separate control of eye and head movements during a gaze shift.

驱动运动神经元（使眼睛移动）的命令的暂存区位于脑干的桥脑和髓质网状结构中。当头部无法转动时，快速的眼球运动（称为扫视）会在释放大量动作电位的脑干神经元的帮助下改变注视方向。 这些突发神经元受到来自神经元的抑制的控制，这些神经元通常稳定放电，但在所有眼跳中都会停止放电或暂停。 在过去的一年中，我们研究了当头部自由转动并且凝视转移由眼睛和头部运动组成时，这些全停神经元（OPN）的暂停是否仍然与眼睛运动最好地相关，或者控制头部持续时间或整体凝视转移的持续时间，即眼睛位置+头部位置。 我们发现停顿持续时间与头部持续时间的相关性较差。 此外，通过将暂停持续时间与运动持续时间相关联，我们无法确定暂停持续时间是否与眼睛或整体凝视持续时间更好地相关。 然而，当我们将停顿的结束与扫视的结束对齐时，停顿几乎总是比注视运动的结束更好地与眼球运动的结束对齐。 因此，我们得出的结论是，位于脑桥的 OPN 与凝视转移的眼睛成分有关，而不是与整体凝视转移或头部运动成分有关。 相反，上述各种突发神经元的放电模式可能与眼睛运动、凝视运动或整体凝视转移更好地相关。 具有这些特征的暂停和爆发神经元非常适合我们的模型，用于在凝视转移期间单独控制眼睛和头部运动。