记忆可能是由某种神经元中的蛋白质簇构成的

纽约，2001年10月18日——哥伦比亚大学内科和外科医生学院的研究人员发现了一种新型的结构变化，这种变化发生在脑细胞在记忆和学习过程中相互交流的过程中。在临床神经生物学和行为学(精神病学)副教授罗伯特·霍金斯博士的领导下，哥伦比亚大学的研究人员，包括诺贝尔奖获得者埃里克·坎德尔及其同事，首次发现了突触前神经元中某些蛋白质聚集方式的快速变化，这被称为长期增强。长期强化是指在与记忆形成相关的过程中突触强度的增加。突触由突触前神经元组成，突触前神经元释放一种叫做神经递质的化学物质，作用于突触后神经元的细胞表面受体，产生神经传递。虽然大多数研究都把重点放在突触后神经元的变化上，认为它是长期增强的场所，但哥伦比亚大学的研究人员现在有了第一个证据，证明突触前神经元的快速结构变化是大脑中记忆路径的另一个场所。霍金斯博士说:“这是与长期强化有关的突触前神经元快速结构变化的第一个证据。”他们的研究结果发表在10月18日的《科学》杂志的《科学快讯》网站上。在这项研究中，研究人员研究了培养的小鼠海马细胞的突触前神经元中所谓的“初级突触囊泡相关蛋白”。神经科学家认为，海马体是大脑中储存记忆的区域。这些蛋白质有助于在神经元内部形成泡状结构，将神经递质携带到神经元表面，释放到突触。 Using fluorescent-labeled antibodies, the researchers found that within minutes of long-term potentiation, these vesicle-associated proteins in the pre-synaptic neurons clustered together. The next step in the research is to understand how these early changes might relate to the formation of memories. Most neuroscientists think that long-term potentiation lasting more than a couple of hours involves the growth of new synapses, which means alterations to both the pre- and post-synaptic neurons. Columbia researchers are trying to find out if changes happen first on one side of the synapse that then cause changes on the other side. Most recent research has focused on post-synaptic changes with some investigators suggesting that changes in the pre-synaptic neurons are passive consequences. “Our research indicates that pre-synaptic changes occur surprisingly rapidly and could precede and even initiate some of the post-synaptic changes,” Dr. Hawkins says. “My own view is that there is probably a fairly elaborate dance with the two partners exchanging signals in both directions so they end up making matching parts of a whole synapse. This is what has been seen at the neuromuscular junction [the site of the transmission of neural impulses and muscle], where these questions have been studied much more extensively.”

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