NEUROTRANSMITTER RECEPTOR DYNAMICS IN VIVO

这个项目的主要目的是更好地了解神经递质受体聚集是如何调节和维持在突触。 将使用新开发的技术来监测活体小鼠个体神经肌肉接头处乙酰胆碱受体数量的变化。这种方法允许在几分钟到几个月的时间内定量从识别的突触的受体添加和丢失的速率。 神经肌肉突触活动的改变将被用来分析突触后活动在调节受体数量中的作用。 使用高分辨率共聚焦显微镜荧光恢复后光漂白，和两个颜色的受体标记，将有助于解决是否新合成的受体被直接添加到交界处或插入到交界区，然后迁移到交界处，他们被困。 最后，这些实验将研究长期阻断神经肌肉传递对神经肌肉接头随后功能的影响。 这个问题在临床上很重要，因为已经用神经肌肉阻滞剂治疗了几天的患者偶尔会在移除阻滞剂后瘫痪几周。这种破坏性综合征的病因尚不清楚，但似乎类似于支持这种应用的初步工作中观察到的神经肌肉阻滞的作用。 由于活动和不活动引起的受体数量的变化被认为是有助于在中枢神经系统的长时程增强和抑郁症，这里提出的研究可能会提供有关活动对突触强度的影响，在较难访问的突触的基本信息。

The main objective of this project is to better understand how neurotransmitter receptor aggregations are regulated and maintained at a synapse. Newly developed techniques for monitoring changes in the number of acetylcholine receptors at individual neuromuscular junctions in living mice will be used. This approach permits quantification of the rates of receptor addition and loss from an identified synapse over periods of minutes to months. Modifications of the activity of the neuromuscular synapse will be used to analyze the role of postsynaptic activity in modulating receptor numbers. The use of high resolution confocal microscopy fluoresce recovery after photobleaching, and two color receptor labeling, will help resolve whether newly synthesized receptors are added directly to the junction or are inserted into the perijunctional region and then migrate to the junction where they are trapped. Lastly, these experiments will examine the consequences of long-term blockade of neuromuscular transmission on the subsequent function of the neuromuscular junction. This question is clinically important because patients who have been treated with neuromuscular blocking agents for several days occasionally remain paralyzed for weeks after removing the blocking agents. The etiology of this devastating syndrome is not known but seems analogous to the effects of neuromuscular blockade observed in the preliminary work that supports this application. Because activity and inactivity induced changes in receptor numbers are thought to be instrumental in long-term potentiation and depression in the central nervous system, the studies proposed here may provide fundamental information concerning the effects of activity on synaptic strength at less accessible synapses.