整合素在海马突触中的功能性前和后突触成熟中介
1CNRS UPR 9023, 141 rue de la Cardonille, 34094 Montpellier Cedex 05, France. chavisp@ccipe.montp.inserm.fr
Nature
|May 18, 2001
概括
整合素是一种细胞粘附分子,对于功能性海马突触的发展至关重要. 阻断整合素信号传递阻止了正常成熟,突出了它们在中枢神经系统突触发育中的作用.
科学领域:
- 神经科学是一个神经科学.
- 细胞生物学 细胞生物学
- 突触性可塑性 突触性可塑性
背景情况:
- 前和后突触神经元之间的协调信号传递对于中枢突触的发育和功能至关重要.
- 细胞粘附分子,以及扩散性分子,可能会在突触中调解双向通信.
研究的目的:
- 为了研究整合素的作用,细胞粘附分子的一类,在功能成熟的海马突触 in vitro.
- 确定整合素信号传导是否影响氨酸释放概率和NMDA受体子单元组成在突触发育期间.
主要方法:
- 关于海马突触的体外研究.
- 使用针对整合素结合位点的Arg-Gly-Asp (RGD) 的慢性阻塞.
- 功能性抗体阻断针对β3整合素子单元.
- 通过对synaptotagmin I.的抗体吸收监测活跃的突触.
主要成果:
- 整合素是 hippocampal 突触的功能成熟所需的.
- 阻断整合素信号传递阻止了依赖活动的减少谷氨酸释放概率 (Pr).
- 集成蛋白阻塞还抑制了后突触NMDA受体子单元组成 (NR2B到NR2A) 的切换.
- 在活跃的突触中检测到β3整合素子单元的免疫活性.
结论:
- 集成因介导的信号传递对于中央刺激突触的编排成熟至关重要.
- 集成蛋白在调节突触功能和发育过程中的可塑性方面发挥着至关重要的作用.
更多相关视频
相关概念视频
Long-term Potentiation
Long-term potentiation, or LTP, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTP is the process of synaptic strengthening that occurs over time between pre- and postsynaptic neuronal connections. The synaptic strengthening of LTP works in opposition to the synaptic weakening of long-term depression (LTD) and together are the main mechanisms that underlie learning and memory.
Long-term Potentiation
Long-term potentiation, or LTP, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTP is the process of synaptic strengthening that occurs over time between pre and postsynaptic neuronal connections. The synaptic strengthening of LTP works in opposition to the synaptic weakening of long-term depression (LTD) and together are the main mechanisms that underlie learning and memory.
Hebbian LTP
LTP can occur when presynaptic neurons...
Hebbian LTP
LTP can occur when presynaptic neurons...
Integrins
Animal and protozoan cells do not have cell walls to help maintain shape and provide structural stability. Instead, these eukaryotic cells secrete a sticky mass of carbohydrates and proteins into the spaces between adjacent cells. This network of proteins and molecules is called an extracellular matrix or ECM.
Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,...
Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,...
Activation of Integrins
Integrins bind ligands and transmit information from outside the cell to inside or vice-versa through an "outside-in signaling" or "inside-out signaling."
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus.
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus.
Intracellular Signaling Affects Focal Adhesions
Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...
Some...
Integration of Synaptic Events
Synaptic integration mainly includes the summation of graded potentials. Graded potentials, regardless of their type, cause subtle alterations in membrane voltage, resulting in either depolarization or hyperpolarization. These incremental changes, when combined or summed, can propel the neuron toward its threshold. Consider, for example, a membrane experiencing a +15 mV shift, causing it to depolarize from -70 mV to -55 mV. In this scenario, graded potentials govern the membrane's ability to...


