「摂食制御の神経回路」の版間の差分

ネコを用いた破壊実験から、腹内側核に満腹中枢があり、外側野に空腹中枢があると考えられてきた。しかし、過去の破壊実験の多くは近傍の神経線維の破壊を伴うため、単純には解釈できない。例えば、外側野の破壊時には内側前脳束も損傷するが、内側前脳束には摂食行動や報酬行動に重要なドパミン神経線維が豊富に存在する。腹内側核を破壊すると、弓状核からの腹内側核や室傍核への投射線維も破壊されるため、観察される摂食行動変化の原因が腹内側核と弓状核のどちらにあるかを決めることができない。しかし、Cre-loxPシステムを利用した遺伝子改変マウスの開発により、特定の神経細胞集団での遺伝子発現変化が摂食行動や体重制御に与える影響を検討することが可能となり、この10年で摂食制御の神経ネットワークについての理解が大きく進展した。  

'''摂食制御に関わる神経核'''  

眼窩前頭皮質は、味覚情報が島皮質周辺を経て集まる他、嗅覚や口腔感覚情報が集まり、摂食時の感覚が統合される。さらに、眼窩前頭皮質は側坐核や扁桃体と密な線維連絡を持ち、報酬行動、意思決定に重要な役割を果たすことが知られている。眼窩前頭皮質は空腹時に活性化し、前頭前皮質の運動の実行開始を制御する部位と密な線維連絡を持つことから、摂食に向かう行動開始の決定と実行に重要であると考えられている(Rolls 2005)。  

*側坐核

<br>  

<u>視床下部</u>  

*弓状核

*&nbsp;　　　NPY/AgRP神経

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