In vitro eye-blink reflex model: role of excitatory amino acids and labeling of network activity with sulforhodamine
In vitro eye-blink reflex model: role of excitatory amino acids and labeling of network activity with sulforhodamine
复制标题
体外眨眼反射模型：兴奋性氨基酸的作用和用磺胺罗丹明标记网络活性
DOI：
10.1007/bf00228693
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发表时间：
2004
影响因子：
2
通讯作者：
J. Keifer
中科院分区：
文献类型：
--
作者：
J. Keifer
有证据表明，神经相关的眨眼反射可以诱发在体外脑干小脑准备从海龟使用电，而不是自然刺激的脑神经输入。外展神经放电由同侧三叉神经的短暂电刺激触发。这种放电在行为上对应于眼外肌的EMG记录和原位记录的眼球回缩，在简化的准备中。外展神经放电具有两个分量：具有3-6 ms的潜伏期和50-100 ms的持续时间的短持续时间响应，随后是具有12-20 ms的潜伏期和几秒的持续时间的长持续时间分量。反射的长持续时间成分被NMDA受体拮抗剂APV阻断，而两种反射反应都被非NMDA谷氨酸受体拮抗剂CNQX阻断。为了使外展神经反射过程中活动的空间分布可视化，使用了活动依赖性染料磺酰罗丹明的浴应用。在反射活动中，神经元在同侧三叉神经核，主展神经核，并假定interneurons腹外侧的主展神经核，标记的染料，除了中缝核和网状结构的地区。在条件下，长时间的反射成分被抑制，磺酰罗丹明标签是缺席的主要展神经核和尾侧脑干。从这些数据，它是假设，该地区的中间神经元和副展神经核参与的短持续时间的组成部分的反射。这种反应由非NMDA受体介导。外展神经主核被认为也对反射的短持续时间部分有贡献，但主要参与长持续时间部分的产生。这种反射成分主要由NMDA受体介导。持续的反射活动被进一步假设为起源于尾侧脑干内的通路中的反复兴奋，特别是网状结构。这种解释是一致的观察模式的磺酰罗丹明标签，局部微量注射APV的影响，并消除持续活动时，尾侧脑干横断。这些数据可能对眨眼反应的调节途径产生影响。
Evidence is presented suggesting that the neural correlate of the eye-blink reflex can be evoked in an in vitro brainstem-cerebellum preparation from the turtle by using electrical rather than natural stimulation of cranial nerve inputs. Abducens nerve discharge is triggered by brief electrical stimulation of the ipsilateral trigeminal nerve. This discharge corresponds behaviorally to EMG recordings of extraocular muscles and eye retraction recorded in situ, in a reduced preparation. The abducens nerve discharge has two components: a short-duration response having a latency of 3–6 ms and a duration of 50-100 ms, followed by a long-duration component having a latency of 12–20 ms and a duration of several seconds. The long-duration component of the reflex is blocked by the NMDA receptor antagonist APV, while both reflex responses are blocked by the non-NMDA glutamate receptor antagonist CNQX. To visualize the spatial distribution of activity during the abducens nerve reflex, bath application of the activity-dependent dye sulforhodamine was used. During reflex activity, neurons in the ipsilateral trigeminal nucleus, principal abducens nucleus, and presumed interneurons ventrolateral to the principal abducens nucleus, labeled with the dye, in addition to areas in the raphe nucleus and reticular formation. In conditions where the long-duration component of the reflex was suppressed, sulforhodamine label was absent in the principal abducens nucleus and in the caudal brainstem. From these data it is hypothesized that the region of interneurons and the accessory abducens nucleus participate in the short-duration component of the reflex. This response is mediated by non-NMDA receptors. The principal abducens nucleus is postulated to contribute also to the short-duration portion of the reflex, but is primarily involved in the generation of the long-duration component. This component of the reflex is mediated principally by NMDA receptors. Sustained reflex activity is further postulated to originate from recurrent excitation in pathways within the caudal brainstem, particularly the reticular formation. This interpretation is consistent with the observed patterns of sulforhodamine label, the effects of local microinjections of APV, and the elimination of sustained activity when the caudal brainstem is transected. These data have implications for pathways that may underlie conditioning of the eye-blink response.