連続したシナプス刺激と阻害は,自発的な行動のための準備状態の放電を形成します
Katsushi Kagaya1, Masakazu Takahata
1Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan. kagaya@sci.hokudai.ac.jp
まとめ
科学者たちは,クレイフィッシュの脳活動が,どのように自発的な行動に備わっているかを発見しました. 準備放電は,神経細胞の連続的な興奮と阻害を伴うもので,自己発起の行動のメカニズムを明らかにします.
科学分野:
- 神経科学は神経科学である.
- 動物の行動 動物の行動
- シナプスの可塑性
背景:
- 動物における自発的な行動の開始は,準備的な神経活動と関連しています.
- この準備を支える特定のニューロンとシナプスメカニズムが完全に理解されていません.
研究 の 目的:
- ボランティア行動を開始する際の準備性放電のニューラル基盤を調査する.
- 準備神経活動に関与するシナプスメカニズムを解明する.
主な方法:
- クラゲ (Procambarus clarkii) の脳における電気生理学的記録.
- 準備解除時のニューロン発火パターンとシナプス相互作用の分析.
主要な成果:
- 準備放電は,連続したシナプス刺激と阻害によって形成されます.
- 準備放電ニューロンは,軸索の付帯線を介してローカルな内部ニューロンを活性化します.
- このプロセスは,下流のガンジアからのフィードバックなしに脳内で起こるようです.
結論:
- 脳内の連続したシナプスイベントによって準備放電が形成されるモデルが提案されています.
- この神経回路は,自己生成の自発的行動開始のための信号処理に適しています.
関連する概念動画
Synaptic 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...
Synaptic 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.
Chemical 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...
Chemical 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...
Excitatory 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...
Integration 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...


