在一个突触终端的异位细胞形成率的依赖性
R Heidelberger1, C Heinemann, E Neher
1Abteilung Membranbiophysik, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.
Nature
|October 6, 1994
概括
这项研究量化了细胞内和神经递质释放之间的关系. 神经终端度的快速增加揭示了突触囊泡融合的高速,这对神经元通信至关重要.
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
- 生物物理学的生物物理.
背景情况:
- 神经递质的释放对神经元通信至关重要.
- 的度和外细胞形成率之间的确切关系尚未完全理解.
研究的目的:
- 量化确定前突触细胞内离子度 ([Ca2+]i) 和外细胞形成率之间的关系.
- 为了确定神经递质分泌的最大速率.
主要方法:
- 使用中的的闪光光电解,在突触终端快速且均地提升[Ca2+]i.
- 测量膜容量作为外细胞分裂的指数.
- 使用指标染料监测[Ca2+]i.
主要成果:
- 随着[Ca2+]i的产生,细胞外率急剧增加,这表明至少有四个离子结合激活核聚变.
- 的半和度为194微米.
- 外细胞形成的最大速率常数为2000-3000s-1.
- 当[Ca2+]i超过100微米时,突触囊泡可以在微秒内具有很高的概率进行异细胞化.
结论:
- 这项研究提供了对依赖性外细胞瘤的动力学的定量见解.
- 这些发现解释了神经元的快速信号传递能力.
相关概念视频
Overview of Secretory Vesicles
Secretory vesicles, also known as dense core vesicles (DCVs), are membrane-bound vesicles that transport secretory proteins, such as hormones or neurotransmitters. Regulated secretory vesicles transport proteins from the trans-Golgi network to the exterior of the cell. Proteins present in regulated secretory vesicles are required to be rapidly exocytosed in large amounts upon a specific stimulus.
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Fusion of Secretory Vesicles with the Plasma Membrane
Proteins and neurotransmitters in secretory vesicles can be released from a cell upon vesicle docking, priming, and fusion with the plasma membrane. Vesicles are docked and primed in preparation for the quick exocytosis of their contents in response to a stimulus. The fusion process is mainly carried out by a SNAP Receptor or SNARE complex, consisting of synaptobrevin, syntaxin-1, and SNAP-25.
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
Chemical Synapses
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Feedback Regulation of Calcium Concentration
Calcium is an essential signaling molecule required for various cellular functions. Calcium pumps and ion channels on cell and organellar membranes, such as those on the endoplasmic reticulum (ER), regulate calcium concentrations inside the cell. They remain closed, keeping the cytosolic calcium levels low at a resting state.
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Ligand-Gated Ion Channel Receptor: Gating Mechanism
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
Chemical Synapses
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...


