シナプスで放出されるグリシンが溢れることで,脊髄NMDA受容体電流の促進
Seifollah Ahmadi1, Uta Muth-Selbach, Andreas Lauterbach
1Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Universität Erlangen-Nürnberg, Fahrstrasse 17, D-91054 Erlangen, Germany.
Science (New York, N.Y.)
|June 28, 2003
まとめ
シナプス的に放出されたグリシンは,表面的背中角のN-メチル-D-アスパルテート (NMDA) 受容体活性を増強する. このグリシン溢出メカニズムは,炎症性疼痛過敏症に寄与する可能性があります.
科学分野:
- 神経科学は神経科学である.
- 痛みに関する研究 痛みに関する研究
- シナプスの可塑性
背景:
- N-メチル-D-アスパルテート (NMDA) 受容体は,哺乳類の中枢神経系 (CNS) のシナプス伝達と可塑性にとって極めて重要です.
- グリシンは,NMDA受容体の活性化に必要な共同アゴニストです.
- 生体内におけるシナプス性NMDA受容体の反応を調節する細胞外グリシンの役割は,依然としてほとんど不明である.
研究 の 目的:
- シナプスで放出されたグリシンが,表面的背中角のNMDA受容体電流に影響するかどうかを調査する.
- グリシン溢出のメカニズムと痛みの処理への貢献を探求する.
主な方法:
- 表面の背中角の電気生理学的記録.
- NMDA受容体電流の調査.
- 高シナプス活性期におけるシナプスグリシン放出と溢出の分析.
主要な成果:
- シナプスで放出されるグリシンは,表面的背中角のNMDA受容体電流を促進することが判明しました.
- 阻害性インターニューロンから放出されたグリシンは,シナプス裂け目から脱出し,溢出経由で近くのNMDA受容体に到達することができます.
- この溢出メカニズムは,高いプレシナプス活動中に観察されます.
結論:
- 阻害性インターニューロンからの溢出によって放出される細胞外グリシンは,シナプス性NMDA受容体の機能を積極的に調節する.
- このメカニズムは,炎症性ハイパーアルゲシアと痛みの伝播の発達に重要な役割を果たす可能性があります.
さらに関連する動画
関連する概念動画
01:35Long-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.
01:29Excitatory and Inhibitory Effects of Neurotransmitters
When an action potential reaches the presynaptic axon terminal, it releases neurotransmitters from the neuron into the synaptic cleft at a chemical synapse. The released neurotransmitter can be excitatory or inhibitory. The critical criteria commonly used to determine whether a molecule is a neurotransmitter at a chemical synapse are the molecule's presence in the presynaptic neuron. Second, its release is in response to strong presynaptic depolarization. And lastly, the presence of specific...
01:19Ligand-gated Ion Channels
Ligand-gated ion channels are transmembrane proteins with a channel for ions to pass through and a binding site for a ligand. The channel opens only when a ligand attaches to the binding site.
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the...
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the...
01:26Chemical 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...
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...
01:26Chemical 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...