Saccadic eye movements evoked by microstimulation of the fastigial nucleus of macaque monkeys.
Saccadic eye movements evoked by microstimulation of the fastigial nucleus of macaque monkeys.
复制标题
猕猴顶核的微刺激引起的眼球扫视运动。
DOI：
10.1152/jn.1988.60.3.1036
复制
发表时间：
1988
影响因子：
2.5
通讯作者：
Aso,T
中科院分区：
文献类型：
--
作者：
Noda,H;Murakami,S;Yamada,J;Tamada,J;Tamaki,Y;Aso,T
1.对小脑深部核团和白色物质的系统研究表明，用弱电流（小于10微安）诱发扫视眼球运动的区域仅限于小脑顶核和邻近的白色物质。2.当用于刺激的电极在小脑中被推进时，当其进入低阈值区域时，在受刺激侧的方向上诱发扫视（同侧扫视）。在某些轨迹中，特别是当电极在小脑顶核的内侧部分推进时，诱发的扫视方向从同侧变为对侧。3.微刺激的映射揭示了同侧扫视是从一个相对较宽的区域引起的，该区域几乎包括顶核的全部范围。低阈值区继续在白色物质尾侧进入蚓状小叶VII和吻侧进入背侧的结合臂。另一方面，对侧眼跳是从小脑顶核腹内侧部的一个相对有限的区域诱发的。4.水平分量方向的反转总是发生在顶核核心的狭窄区域。该区域的尾部与一个椭圆形区域相吻合，当HRP注入到蚓小叶VII时，浦肯野细胞的顺行标记轴突终止于该区域。5.当荷包牡丹碱（0.2-1微克）注射在椭圆形区域，同侧扫视诱发的背尾侧的区域被抑制了几个小时。另一方面，从小脑顶核腹内侧部诱发的对侧扫视没有变化或增强。6.由于同侧扫视被荷包牡丹碱抑制，它们最有可能是由γ-氨基丁酸（GABA）介导的突触，即浦肯野细胞的轴突的突触前成分的刺激引起的。7.因为刺激抑制性突触的突触前成分会引起同侧扫视，激活突触后成分会引起对侧扫视。事实上，产生对侧扫视的小脑顶部位的分布与椭圆体区域中产生的小脑顶神经元轴突的过程相吻合。因此，最有可能的是，对侧扫视是由刺激小脑顶神经元引起的。（400字处删节）
1. Systematic exploration throughout the deep cerebellar nuclei and white matter disclosed that the region from which saccadic eye movements (saccades) were evoked with weak currents (less than 10 microA) was confined to the fastigial nucleus and the adjacent white matter. 2. When an electrode for stimulation was advanced in the cerebellum, saccades were evoked in the direction of the stimulated side (ipsilateral saccades) as it entered the low-threshold region. In some tracks, particularly when the electrode was advanced in the medial portion of the fastigial nucleus, the direction of the evoked saccades changed from the ipsilateral to the contralateral. 3. The mappings with microstimulation disclosed that the ipsilateral saccades were elicited from a relatively wide region that included almost the full extent of the fastigial nucleus. The low-threshold region continued in the white matter caudally into vermal lobule VII and rostrally into the dorsal aspect of the brachium conjunctivum. On the other hand, the contralateral saccades were evoked from a relatively circumscribed region in the ventromedial portion of the fastigial nucleus. 4. The reversal in the direction of the horizontal component occurred always in a narrow zone in the core of the fastigial nucleus. The caudal part of this zone coincided with an ellipsoidal region where anterogradely labeled axons of the Purkinje cells terminated when HRP was injected into vermal lobule VII. 5. When bicuculline (0.2-1 microgram) was injected in the ellipsoidal region, the ipsilateral saccades evoked from the dorsocaudal aspect of the region were suppressed for several hours. On the other hand, the contralateral saccades evoked from the ventromedial portion of the fastigial nucleus were either unchanged or enhanced. 6. Because the ipsilateral saccades were suppressed by bicuculline, they were most probably evoked by stimulation of the presynaptic component of gamma-amino-butyric acid-(GABA) mediated synapses, namely the axons of Purkinje cells. 7. Because stimulation of the presynaptic component of the inhibitory synapses evoked ipsilateral saccades, activation of the postsynaptic component would evoke contralateral saccades. In fact, the distribution of the fastigial sites yielding contralateral saccades coincided with the course of axons of fastigial neurons arising in the ellipsoidal region. It is most likely, therefore, that the contralateral saccades were evoked by stimulation of fastigial neurons.(ABSTRACT TRUNCATED AT 400 WORDS)