对Ca2+信号的整合和射击方法. 第二部分:累积的折射性
Lukas Ramlow1, Martin Falcke2, Benjamin Lindner3
1Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany; Department of Physics, Humboldt University Berlin, Berlin, Germany; Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Biophysical journal
|November 20, 2023
概括
(Ca2+) 信号频率编码了刺激度. 一个新的模型解释了Ca2+峰值中的累积折射性,匹配实验数据并揭示了适应机制.
科学领域:
- 蜂信号传输是如何进行的
- 生物物理学的生物物理.
- 计算生物学是一种计算生物学.
背景情况:
- 伊诺西1,4,5-三酸盐 (IP3) 诱导的Ca2+信号传递是真核细胞中基本的第二信使系统.
- 刺激度编码在Ca2+度峰值序列的频率中.
- 细胞表现出累积折射性,刺激时间隙间隔 (ISI) 短暂增加.
研究的目的:
- 通过将细胞内Ca2+储存度作为适应变量来扩展Ca2+信号的随机模型.
- 复制和解释实验观察到的ISI序列的静态和瞬态统计数据.
- 调查适应,ISI统计和相关性之间的关系.
主要方法:
- 开发了一个扩展的随机模型,包括细胞内Ca2+储存适应.
- 对于静态ISI统计的近似表达式的推导 (平均值和变化系数).
- 将模型与来自刺激的HEK细胞的实验ISI序列相匹配.
主要成果:
- 该模型成功地复制了实验ISI序列的静态和瞬态统计数据.
- 估计了适应强度,与实验观测保持一致,并解释了变化系数.
- 该模型解释了弱的ISI相关性,尽管明显的短暂行为.
- 模型与HEK细胞数据相匹配,重现了相关性,短暂间隔和适应强度之间的定性关系.
结论:
- 扩展的随机模型为理解IP3诱导的Ca2+信号动态和适应提供了一个强大的框架.
- 该模型阐明了细胞内Ca2+储存适应在塑造ISI频率和相关性中的作用.
- 模型预测和实验数据之间的差异,特别是关于正相关性的差异,突出了未来研究的领域.
更多相关视频
相关概念视频
The Role of Ion Channels in Neuronal Computation
3.2K
A postsynaptic neuron usually receives numerous impulses from several other presynaptic neurons. The axon hillock of the postsynaptic neuron integrates all these signals and determines the likelihood of firing an action potential.
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential....
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential....
3.2K
Integration of Synaptic Events
1.5K
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...
1.5K
Feedback Regulation of Calcium Concentration
3.4K
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...
3.4K
Ligand-Gated Ion Channel Receptor: Gating Mechanism
2.3K
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...
2.3K
Relaxation of Skeletal Muscles
3.3K
The period of muscle contraction primarily influences the duration of stimulation at the neuromuscular junction (NMJ), the presence of free calcium ions in the sarcoplasm, and the availability of energy or ATP to support contractions.
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open....
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open....
3.3K
Calmodulin-dependent Signaling
5.2K
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
5.2K


