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Updated: Jul 27, 2026
11:02
Presynaptically Silent Synapses Studied with Light Microscopy
Published on: January 4, 2010
単一のニューロンの端末でシナプス効果のシナプス固有の制御
1Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720, USA. gdavis@coreys.berkeley.edu
Nature
|March 24, 1998
まとめ
筋肉のサイズと内置は,2つの異なるメカニズムを通してシナプス効果に影響します. この研究は,筋肉がどのように神経細胞のコミュニケーションを調節し,適切な神経回路の機能を保証するかを明らかにします.
科学分野:
- 神経科学は神経科学である.
- シナプスの可塑性
- モーターニューロンの規制
背景:
- シナプスの有効性は神経回路の機能にとって極めて重要であり,異常なニューロンの活動を避けるために正確な調節が必要です.
- シナプスは,継続的に再構築されるダイナミックな構造であり,安定した神経機能のためにホメオスタティックなメカニズムを必要とします.
- 神経筋交差点 (NMJ) は,筋肉のサイズと知られているリンクを持つシナプス有効性調節を研究するためのモデルシステムとして機能します.
研究 の 目的:
- 筋肉がモーターニューロン端末のシナプス効果を調節するメカニズムを調査する.
- 筋肉から派生した信号が,筋肉のサイズとシナプス効果の間の結合を媒介するかどうかを判断する.
- 筋肉と神経のコミュニケーションに関与する特定の分子経路の解明.
主な方法:
- モデル生物における筋肉内膜の遺伝子操作.
- 神経筋交差点におけるシナプス前伝達器の放出の分析.
- シナプス効果と定量サイズの定量化.
主要な成果:
- 筋肉内置の増加は,前シナプス伝達器の放出を補償し,ターゲットに特異的に減少させ,逆行シグナル伝達を示唆しました.
- 筋肉内置の減少は,量子的な大きさの補償的な増加をもたらしました.
- モーターニューロン端末のシナプス効果を調節する2つの独立した筋肉由来メカニズムが特定されました.
結論:
- 筋肉は,少なくとも2つの異なる経路を通って,神経筋肉の交差点でのシナプス効果を積極的に調節します.
- 筋肉からモーターニューロンへの逆行信号は,シナプス前放出を調節する.
- 量子サイズの変化は,筋肉がシナプス強度に影響を与えるもう一つのメカニズムを表しています.
関連する概念動画
01:12Synaptic Signaling
Neurons communicate at synapses, or junctions, to excite or inhibit the activity of other neurons or target cells, such as muscles. Synapses may be chemical or electrical.
02:47The Synapse
Neurons communicate with one another by passing on their electrical signals to other neurons. A synapse is the location where two neurons meet to exchange signals. At the synapse, the neuron that sends the signal is called the presynaptic cell, while the neuron that receives the message is called the postsynaptic cell. Note that most neurons can be both presynaptic and postsynaptic, as they both transmit and receive information.
01:09Synaptic Signaling
Neurons communicate at synapses, or junctions, to excite or inhibit the activity of other neurons or target cells, such as muscles. Synapses may be chemical or electrical.
Most synapses are chemical, meaning an electrical impulse or action potential spurs the release of chemical messengers called neurotransmitters. The neuron sending the signal is called the presynaptic neuron, and the neuron receiving the signal is the postsynaptic neuron.
The presynaptic neuron fires an action potential that...
Most synapses are chemical, meaning an electrical impulse or action potential spurs the release of chemical messengers called neurotransmitters. The neuron sending the signal is called the presynaptic neuron, and the neuron receiving the signal is the postsynaptic neuron.
The presynaptic neuron fires an action potential that...
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...
01:26Chemical 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...
01:28Integration of Synaptic Events
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...