脊椎動物の嗅覚受容体細胞のオドラント誘発電流におけるカチオンと塩化物の共存

T Kurahashi¹, K W Yau

¹Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.

Nature

|May 6, 1993

まとめ

嗅覚受容体ニューロンは,匂い伝達のための新しい二重メカニズムを使用します. 新たに発見された塩化物電流は,カチオン電流とともに,反応を安定させ,嗅覚研究における以前の観察を説明する.

科学分野:

神経科学は神経科学である.
感覚生物学感覚生物学について
分子生物学は分子生物学である.

背景:

嗅覚受容体ニューロンは,匂い刺激によって脱極化します.
現在のモデルでは,Gタンパク質/cAMPまたはフォスフォリファースC経路がカチオン流入につながる.
これらの経路は,受容体ポテンシャルのみを生成すると考えられていた.

研究の目的:

嗅覚受容体ニューロンにおけるオドラント誘発の脱極化の完全なメカニズムを調査する.
嗅覚伝導のイオン基を解明する.
外部イオン濃度の変化に対する嗅覚反応の強さを説明する.

主な方法:

嗅覚受容体ニューロンからの電気生理学的記録.
オドラント誘発の電流の分析.
嗅覚応答のイオン依存性の調査.

主要な成果:

匂い刺激は,カチオンの成分と塩化物の成分の両方を含む複雑な電流を誘発する.
カチオンチャネルを通るカルシウムの流入によって,内向きの塩化物流が誘発されます.
この塩化物の成分は,カチオンの成分と同じくらい大きくなります.
二重電流のメカニズムは,感覚伝導経路の中で潜在的にユニークです.

結論:

嗅覚伝導は,以前に理解されていたよりも複雑なメカニズムを含み,カチオンとクロライドの両方の電流を組み込む.
この二重のイオンメカニズムは,環境のイオン変動に対する嗅覚応答に安定性を与える可能性があります.
この発見は,外部のカチオンが除去されても,なぜ嗅覚反応が持続するのかという長年の疑問を解決している.

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