双方向シナプス性可塑性におけるAMPA受容体の異なるリン酸化部位の調節
H K Lee1, M Barbarosie, K Kameyama
1Howard Hughes Medical Institute, Department of Neuroscience, Johns Hopkins Medical School, Baltimore, Maryland, USA.
Nature
|July 6, 2000
まとめ
長期増強 (LTP) や抑うつ (LTD) のようなシナプス可塑性には,AMPA受容体のリン酸化が含まれています. これらのプロセスは,以前のシナプス活動に応じて,GluR1サブユニットの異なる部位を修正し,歴史に依存するシグナル伝達経路を明らかにします.
科学分野:
- 神経科学は神経科学である.
- 分子生物学は分子生物学である.
- シナプスの可塑性
背景:
- 海馬の長期増強 (LTP) と長期抑うつ (LTD) を含むニューロンシナプス伝達効率の変化は,脳の情報保存に不可欠です.
- AMPA (アルファ-アミノ-3-ヒドロキシ-5-メチル-4-イソクサゾロエプロイオン酸) 受容体の酸化を調節することで,LTPとLTDを媒介すると仮定されています.
研究 の 目的:
- LTPとLTDにおけるAMPA受容体GluR1サブユニットリン酸化の役割を調査する.
- LTPとLTDは,同じリン酸化部位または異なる部位の逆調節を含んでいるかどうかを判断する.
- LTPとLTDの間に活性化される信号経路に対するシナプス経歴の影響を調査する.
主な方法:
- LTPとLTDの間,AMPA受容体GluR1サブユニットリン酸化における可逆的な変化を研究した.
- LTPおよびLTD誘導に関連したフォスフォリレーション部位特異性を調べました.
- 以前のシナプス増強または抑うつが後の可塑性誘導に与える影響を調査した.
- シナプス経歴に基づいて,CaMKIIおよびPKA阻害剤に対するLTPの異なる感受性を評価した.
主要な成果:
- LTPとLTDはAMPA受容体のGluR1サブユニットリン酸化を逆転的に変化させる.
- LTPとLTDは,異なるGluR1リン酸化部位を調節しますが,逆の部位ではありません.
- シナプスの経歴は,どのリン酸化部位が調節されているかを決定する:ナイブシナプスのPKA部位と潜在シナプスのCaMKII部位におけるLTDは,リン酸化を抑制する.
- LTPは,ナイブシナプスのCaMKII部位と,うつしたシナプスのPKA部位のリン酸化を誘導する.
- CaMKIIおよびPKA阻害剤に対するLTPの感受性は,シナプス経歴によって異なります.
結論:
- AMPA受容体のリン酸化はシナプス可塑性にとって不可欠である.
- シナプス性可塑性メカニズムは,単純な逆ではなく,異なるリン酸化部位を含む.
- 同様の刺激条件によって招集される信号伝達経路は,シナプスの以前の活動歴に依存する.
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