An evaluation of synapse independence
An evaluation of synapse independence
复制标题
DOI：
10.1523/jneurosci.21-20-07969.2001
复制
发表时间：
2001-10-15
影响因子：
5.3
通讯作者：
Barbour, B
中科院分区：
文献类型：
--
作者：
Barbour, B
如果像人们普遍认为的那样，信息作为突触效能的分布式修改存储在大脑中，那么可以辩称，如果独立运作的突触数量尽可能多，大脑的存储容量就会最大化。大脑中的大多数突触是谷氨酸能的；如果一个突触释放的谷氨酸能显著激活相邻突触的受体，它们的独立性将受到损害。目前还没有关于囊泡释放后的“溢出”是否会显著激活邻近突触上的受体的一致意见。为了评估中枢突触的独立性，有必要将突触反应与邻近突触通过谷氨酸溢出产生的反应进行比较。在这里，突触激活和溢出反应是在一个模型中模拟的，该模型基于海马体突触的数据，该模型包括突触外空间的近似表示。最近发表的关于谷氨酸转运体分布和性质的数据被纳入其中。研究了可能影响突触或溢出反应的因素。对于一个囊泡的释放，估计最近邻近突触的平均反应将是
If, as is widely believed, information is stored in the brain as distributed modifications of synaptic efficacy, it can be argued that the storage capacity of the brain will be maximized if the number of synapses that operate independently is as large as possible. The majority of synapses in the brain are glutamatergic; their independence will be compromised if glutamate released at one synapse can significantly activate receptors at neighboring synapses. There is currently no agreement on whether "spillover" after the liberation of a vesicle will significantly activate receptors at neighboring synapses. To evaluate the independence of central synapses, it is necessary to compare synaptic responses with those generated at neighboring synapses by glutamate spillover. Here, synaptic activation and spillover responses are simulated in a model, based on data for hippocampal synapses, that includes an approximate representation of the extrasynaptic space. Recently-published data on glutamate transporter distribution and properties are incorporated. Factors likely to influence synaptic or spillover responses are investigated. For release of one vesicle, it is estimated that the mean response at the nearest neighboring synapse will be