神経伝達は,シナプス形成を選択的に制御し,in vivoの並列回路でシナプスを形成する

Daniel Kerschensteiner¹, Josh L Morgan, Edward D Parker

¹Department of Anatomy and Neurobiology, Washington University School of Medicine, St Louis, Missouri 63110, USA. KerschensteinerD@vision.wustl.edu

Nature

|August 21, 2009

まとめ

神経活動は,発達の過程でシナプスの形成に選択的に影響し,除去には影響しない. この研究は,特定の神経経路が接続を精製する方法を明らかにし,シナプス可塑性の以前のモデルに挑戦しています.

科学分野:

神経科学は神経科学である.
発達生物学発達生物学について
シナプスの可塑性

背景:

神経活動が,発達中の神経系におけるシナプス接続パターンを導くと考えられています.
入力活動の差異は,活動性の低いシナプスを排除し,より活発なシナプスを強化すると考えられています.

研究の目的:

シナプスの発達における神経活動の役割を調査する.
活動だけがシナプスの除去を促すという一般的な概念に異議を唱えるために.
活動に依存した回路の精製に関する新しい視点を提示する.

主な方法:

特定の網膜双極性細胞の入力 (ON細胞) を沈黙させるために,テタヌス毒素 (TeNT) を発現するトランス遺伝子マウスを生成した.
タイムラップス画像を用いて,シナプス形成と消去の動態を観察した.
TeNT発現マウスと対照マウスを用いて網膜のギャングリオン細胞 (RGC) のシナプス構造を分析した.

主要な成果:

TeNTマウスのON RGCは,静止されたON双極性細胞でシナプスが少なくなり,これは主にシナプス形成が減少したためであり,除去が増加していないためです.
TeNTを発現するON双極性細胞軸索は,より少ない活性ゾーンを示し,シナプスリボン募集が変化しました.
ON-OFF RGCは入力収束を維持したが,ONアーバーではシナプス数が減少した.

結論:

アクティビティは,回路の発達において選択的な役割を果たし,主にシナプス形成を制御するのでなく,除去を制御する.
アクティビティはシナプスの数に影響するが,デンドリットや軸索のパターンは影響しない.
パラレル処理ストリームの精製は,収束シナプスでも独立して発生します.

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