ヒトの海馬神経生成は,子供では急激に低下し,成人では検出できないレベルに達する
Shawn F Sorrells1,2, Mercedes F Paredes1,3, Arantxa Cebrian-Silla4
1Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, California 94143, USA.
Nature
|March 8, 2018
まとめ
成人ヒトの海馬神経生成は稀で,最初の1年後に神経細胞の生成は急激に減少する. これは他の種と対照的であり,歯周の機能について疑問を投げかけます.
科学分野:
- 神経科学
- 発達生物学
- 人間の解剖学
背景:
- 大人の海馬の神経生成は 認知機能と神経疾患に関連しています
- 過去の研究では,成人ヒトの海馬におけるニューロン生成の程度について 矛盾する証拠が示されています.
- 大人のヒトの海馬は絶えずニューロンを 生み出していると広く信じられています
研究 の 目的:
- ヒトのヒポカンプスにおける ニューロゲネシスの発達経路を調査する
- エピレプシー患者を含む成人の歯状回に若いニューロンが存在するかどうかを判断する.
- ヒトとヒト以外の霊長類のヒポカンプの ニューロゲネシスパターンを比較する
主な方法:
- ヒトの胎児,産後,成人脳組織 (患者を含む) の分析
- 歯状回における原始細胞と若いニューロンを特定するための免疫ヒストキミカル染色.
- マカカ・ムラッタ (猿) の海馬サンプルを用いた比較研究
主要な成果:
- ヒトの発達過程で,サブグラニュラールゾーンでは,定義された原始細胞集団はありません.
- 生後1年以内に 増殖する親細胞と若い神経細胞の急激な減少
- 成人人歯周 (18~77歳) との患者で検出可能な若い神経細胞の欠如.
- ニューロゲネシスは 産後初期に存在しますが 幼年期には著しく減少します
結論:
- 霊長類のヒポカンプスに 新しいニューロンの増殖は 生命の初期に急速に減少します
- 成人ヒトの歯状回における神経生成は存在しないか,極めて稀である.
- ヒトにおけるヒポカンプス神経生成の早期停止は,成人の神経生成が持続した種と比較して機能的な違いを示唆する.
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