視覚皮質の方向選択性と一致する
L Federico Rossi1, Kenneth D Harris2, Matteo Carandini3
1UCL Institute of Ophthalmology, University College London, London, UK. federico.rossi@ucl.ac.uk.
Nature
|November 12, 2020
まとめ
視覚皮質のニューロン選択性は,刺激と抑制の接続の正確な空間パターンから生じ,シナプス前ニューロン選択性から生じません. この回路のモチーフは 感覚処理において 定理的かもしれない.
科学分野:
- 神経科学
- 計算神経科学
- システム神経科学
背景:
- 神経応答の選択性は,刺激と抑制の相互作用によって形成されます.
- 主要視野皮質では,オリエンテーションと方向性のための層2/3のニューロン選択性は,同様に選択的な皮質内入力と伝統的に関連しています.
- しかし,刺激的なインプットには様々な好みがあり,抑制的なインプットには選択性が欠けることがあります.
研究 の 目的:
- ネズミの視覚皮質の2/3層の神経への刺激性および抑制性皮質内接続の正確な空間的組織を調査する.
- 個々の選択性ではなく,入力の空間的配置がニューロン応答の選択性の根底にあるかどうかを判断する.
- 感覚処理における観測された回路モチーフの潜在的正規性を探求する.
主な方法:
- 個々の層2/3のピラミッドニューロンに刺激的および阻害的インプットをラベルし,機能的にイメージする狂犬病の追跡技術を使用した.
- 前シナプスニューロンと後シナプスニューロンの空間的分布と接続パターンを分析した.
- インプット集合の空間的移動と,ポストシナプスニューロンの方向選択性を相関させた.
主要な成果:
- プレシナプス刺激性ニューロンは,2/3と4の層で,ポストシナプスニューロンの好ましい方向で共軸的に分布し,好ましい方向の反対の領域を好むことが判明した.
- プレシナプス抑制ニューロンは,層2/3のポストシナプスニューロンの近く,そしてその好ましい方向の先にある.
- 後シナプス神経の方向選択性は前シナプス神経の選択性とは無関係だったが,刺激と阻害のインプットの空間的配置と相関していた.
結論:
- 前シナプス的な選択性ではなく,刺激的および阻害的皮質内接続の正確な空間的パターンは,視覚皮質の2/3層のニューロン応答の選択性を決定する.
- 観察された非対称な接続性,刺激的および抑制的入力のための明確な空間的配置は,網膜の方向選択性に見られるメカニズムを反映しています.
- これは,感覚処理経路の方向選択性を確立するための潜在的に正規の回路モチーフを示唆する.
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