関連する実験動画
Updated: Aug 11, 2026
08:54
Immunohistochemical and Calcium Imaging Methods in Wholemount Rat Retina
Published on: October 13, 2014
まとめ
グリア細胞,特に網膜のミュラー細胞は,電気刺激性を示す. これらの細胞は,電圧に依存するイオンチャネルを有しており,グリアル細胞は電気的に不活性であるという伝統的な見解に異議を唱えています.
科学分野:
- 神経科学は神経科学である.
- 細胞生物学 細胞生物学
- オフタルモロジック (眼科)
背景:
- 中枢神経系に豊富に存在する膠質細胞は,歴史的に電気的に興奮できないと考えられていた.
- 新興の証拠は,培養中のいくつかの膠質細胞は,電圧に依存するイオンチャネルを持っていることを示唆しています.
- 膠質細胞におけるこれらのチャネルのin vivo存在と機能は,大部分未確認のままでした.
研究 の 目的:
- 脊椎動物の網膜の主要な膠質細胞であるミュラー細胞の電気的性質を調査する.
- ミュラー細胞が電圧依存のイオンチャネル活性を示すかどうかを in situ で判定する.
- 網膜機能と電気生理学におけるこれらのチャネルの潜在的な役割を調査する.
主な方法:
- "Ca2+スパイク"を含む電気生理学的記録は,新鮮に切断された網膜のスライスで実施されました.
- ボルテージ・クランプ・テクニックは,酵素的に解離されたミュラー細胞に適用された.
- 異なるタイプの電圧依存イオンチャネルの識別と特徴付け.
主要な成果:
- 網膜組織におけるミュラー細胞は",Ca2+スパイク"を生成する能力を示した.
- 圧圧クランプの研究では,ミュラー細胞の電圧依存イオンチャネルが4種類あることが明らかになった:Ca2+,Ca2+活性化K+,迅速無活性化K+ (タイプA),および内側修正K+チャネル.
- これらの発見は,Müller細胞の機能的なイオンチャネルの存在をin vivoで確認しています.
結論:
- ミュラー電池は電気的に活性であり,様々な電圧に依存するイオンチャネルを持っています.
- これらのイオンチャネルは,網膜内の細胞外カリウム (K+) の調節におけるミュラー細胞の役割に貢献している可能性が高い.
- 特定されたイオンチャネルは,電網光学図 (ERG) の生成に役割を果たす可能性があります.
関連する概念動画
01:24Non-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.
01:19The 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.
01:26Voltage-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...
01:21G-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,...
01:30Ligand-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...
01:26Voltage-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...