微弱な電場に対する生物の反応:熱ノイズ限界線
1Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge 02139.
Science (New York, N.Y.)
|January 26, 1990
まとめ
細胞は,そのサイズと膜電位の変動をモデル化することによって,弱い電場を検出することができます. 信号の平均化または狭帯域応答により,10〜6V/cmの低周波の電場を検出でき,熱ノイズ制限を超えることができます.
科学分野:
- バイオフィジックス 生物物理学
- 細胞電気生理学 細胞電気生理学
背景:
- 細胞は,熱の変動によって影響される膜ポテンシャルを持っています.
- 適用された電場は,細胞膜ポテンシャルを変化させることができます.
研究 の 目的:
- 弱い電場を細胞で検出するための物理モデルを開発する.
- 細胞サイズ,熱ノイズ,および電場反応との関係を確立するために.
- 亜熱電場を検出するための条件を特定する.
主な方法:
- 細胞を電場検出器として考える物理モデル.
- 熱によって誘発された膜電位変動の分析.
- 適用フィールドの下での最大膜ポテンシャル変化の計算.
- 酵素活性による信号平均のモデリング.
主要な成果:
- 細胞サイズと膜ポテンシャルダイナミクスの間の一般的な関係が導出されました.
- このモデルは,直接的なマクロ分子反応のための最小の電場 (~10~-3) V/cm) を推定しています.
- 狭帯域周波数応答または信号平均は,はるかに弱いフィールド (~10~-6) V/cm) の検出を可能にします.
結論:
- 細胞のサイズは,電場に対する感受性に影響します.
- 信号処理メカニズム (狭帯域または平均) は,電場検出を強化します.
- このモデルは,実験結果と熱ノイズ制限を調和させています.
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