BRAIN GANGLIOSIDES AND MEMORY FORMATION
BRAIN GANGLIOSIDES AND MEMORY FORMATION
复制标题
DOI：
10.1016/0166-4328(94)00131-x
复制
发表时间：
1995-01-23
影响因子：
2.7
通讯作者：
RAHMANN, H
中科院分区：
文献类型：
--
作者：
RAHMANN, H
人们普遍认为，通过稳定突触接触来促进神经元回路的分子过程代表了记忆形成的结构基础。在突触接触的不同区域发生以下基本事件：突触膜外表面电场强度的改变，膜结合功能蛋白（离子通道，离子泵，受体）的构象变化和第二信使级联的激活。最后，通过逆行和顺行神经元运输，突触终末和它们的细胞体之间存在营养反馈，这保证了新形成的突触连接的稳定。由于细胞外间隙（mM Ca 2+浓度）和突触质（μ M Ca 2+）之间的受控Ca 2+交换对于所有这些事件都是必不可少的，因此本研究集中于突触膜外叶处Ca 2+介导的初级信使系统和Ca 2+介导的调节机制。这些使得尽管环境温度可能已经改变，但始终有效的电响应性成为可能。在这方面，神经节苷脂是含有鞘糖脂的两亲性唾液酸，其在突触膜中以复杂的组合物高度积累，发挥重要作用。根据特定的物理化学性质，它们被认为是与钙有关的神经调质，从而有助于信息的传递和存储。一系列来自神经学、生态生理学、行为科学、电子显微镜、生物化学和物理化学的实验结果为这一概念提供了强有力的旁证。
It is generally accepted that the process of molecular facilitation of neuronal circuits by means of stabilization of synaptic contacts represents the structural basis for memory formation. At the distinct zone of synaptic contact the following basic events occur: alterations of the electrical field strength at the outer surface of synaptic membranes, conformational changes of membrane-bound functional proteins (ion channels, ion pumps, receptors) and activation of second messenger cascade. Finally a trophic feed-back between synaptic terminals and their cell bodies through retro- and anterograde neuronal transport exists, which guarantees a stabilization of the newly formed synaptic connection. As a controlled Ca2+-exchange between the extracellular space (mM Ca2+-concentration) and the synaptoplasm (mu M Ca2+) is essential for all these events, the present reseach concentrates on Ca2+-mediated primary messenger systems at the outer leaflet of synaptic membranes and on Ca2+-mediated modulatory mechanisms. These enable an always efficient electroresponsiveness although the environmental temperature might have changed. In this regard gangliosides being amphiphilic sialic acid containing glycosphingolipids, which are highly accumulated in complex composition in synaptic membranes play an important role. According to specific physico-chemical properties, they are assumed to fulfill the task of neuromodulators in connection with calcium, and thus contribute to the transmission and storage of information. The outcome of a series of experiments derived from neurology, ecophysiology, behavioral sciences, electron microscopy, biochemistry and physical chemistry give strong circumstantial evidence for this concept.