長期の増強のシナプス特異性は,短距離で崩壊する
1Max Planck Institute for Psychiatry, München-Martinsried, Germany.
Nature
|July 17, 1997
まとめ
長期増強 (LTP) は,誘導時に活性化されていないシナプスでさえ,近くのシナプスに広がります. この発見は,学習と記憶に不可欠なシナプス性可塑性における入力特異性に関する伝統的な見解に異議を唱える.
科学分野:
- 神経科学は神経科学である.
- シナプスの可塑性
- 細胞メカニズム 細胞メカニズム
背景:
- 長期増強 (LTP) は,学習と記憶の重要なメカニズムです.
- 伝統的に,LTPは活性化されたシナプスでのみ誘発されると考えられていた.
- 最近の研究では,LTPが隣接するニューロンに広がることが示されていますが,入力繊維への広がりは議論の余地があります.
研究 の 目的:
- より細かい空間的なスケールでLTPの入力特異性を調査する.
- LTPが非活性化されたシナプスに広がる正確な距離を決定する.
主な方法:
- 新しいローカル・スーパーフュージョン・テクニックを用いた.
- 高空間解像度 (~30ミクロン) のLTPのシナプス特異性を評価した.
主要な成果:
- LTPは,誘導部位から70μ以内のシナプスに広がった.
- 近隣のシナプスでは,活性化経歴に関係なく,増強が起こりました.
- より遠くにあるシナプスは増強を示さず,限られた広がりを示した.
結論:
- シナプス可塑性,特にLTPは,近距離での入力特異性の欠如を示しています.
- LTPの拡散は空間的に制限され,近くの入力ファイバーに影響します.
- これらの発見は,シナプス改変とニューラル回路におけるその役割に関する私たちの理解を洗練します.
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.
01:05Long-term Depression
Long-term depression, or LTD, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTD is the process of synaptic weakening that occurs over time between pre and postsynaptic neuronal connections. The synaptic weakening of LTD works in opposition to synaptic strengthening by long-term potentiation (LTP) and together are the main mechanisms that underlie learning and memory.
01:25Long-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.
Hebbian LTP
LTP can occur when presynaptic neurons...
Hebbian LTP
LTP can occur when presynaptic neurons...
01:03Long-term Depression
Long-term depression, or LTD, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTD is the process of synaptic weakening that occurs over time between pre and postsynaptic neuronal connections. The synaptic weakening of LTD works in opposition to synaptic strengthening by long-term potentiation (LTP) and together are the main mechanisms that underlie learning and memory.
Calcium Ion Concentration Mechanism
If over time, all...
Calcium Ion Concentration Mechanism
If over time, all...
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...