相关实验视频
Updated: Aug 11, 2026

08:54
Immunohistochemical and Calcium Imaging Methods in Wholemount Rat Retina
Published on: October 13, 2014
概括
质细胞,特别是视网膜中的米勒细胞,表现出电刺激性. 这些细胞具有电压依赖的离子通道,挑战了传统的视角,认为质细胞在电力上不活跃.
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
- 眼科医生 眼科 眼科
背景情况:
- 在中枢神经系统中丰富的质细胞,历史上被认为是电气不可兴奋的.
- 新出现的证据表明,培养中的某些质细胞具有电压依赖的离子通道.
- 这些通道在质细胞中的体内存在和功能在很大程度上仍未得到证实.
研究的目的:
- 为了研究米勒细胞的电特性,脊椎动物视网膜中的主要质细胞.
- 为了确定Müller细胞是否在现场表现出电压依赖的离子通道活性.
- 探索这些通道在视网膜功能和电生理学中的潜在作用.
主要方法:
- 在新切割的视网膜片上进行了包括"Ca2+尖峰"在内的电生理学记录.
- 应用于酶分离的穆勒细胞的电压技术.
- 识别和描述不同类型的电压依赖离子通道.
主要成果:
- 视网膜组织中的穆勒细胞显示出产生"Ca2+尖峰"的能力.
- 电压研究揭示了米勒细胞中四种电压依赖的离子通道类型:Ca2+,Ca2+激活的K+,快速失活的K+ (A型) 和向内纠正的K+通道.
- 这些发现证实了Müller细胞体内有功能性离子通道的存在.
结论:
- 穆勒电池是电活性的,并且具有多种电压依赖的离子通道.
- 这些离子通道可能有助于穆勒细胞在视网膜中调节细胞外 (K+) 的作用.
- 已识别的离子通道可能在产生电网红图 (ERG) 中发挥作用.
相关概念视频
Non-gated Ion Channels
Ion channels are specialized proteins on the plasma membrane that allow charged ions to pass down their electrochemical gradient. Their main function is to maintain the membrane potential which is critical for cell viability. These channels are either gated or non-gated and can transport more than a thousand ions within milliseconds for the cellular event to occur.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
The Role of Ion Channels in Neuronal Computation
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.
Voltage-gated Ion Channels
Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
G-Protein Gated Ion Channels
GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory organs,...
Sensory organs,...
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...
Voltage-gated Ion Channels
Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...

