研究揭示全身麻醉的工作機制

研究揭示全身麻醉的工作機制

作者：

小柯機器人

發布時間：2020/2/23 13:03:43

德國柏林洪堡大學Mototaka Suzuki等研究人員發現，全身麻醉解耦皮質錐體神經元。相關論文於2020年2月20日發表在《細胞》雜誌上。

研究人員發現，三種不同的麻醉劑對小鼠皮質第5層錐體神經元的頂端樹突信號具有相同的破壞性影響。他們發現，在清醒條件下，遠端頂端樹突的光遺傳學去極化作用在細胞體上引起強烈的脈衝，並被麻醉阻滯。此外，研究人員發現阻斷代謝型穀氨酸和膽鹼能受體對頂端樹突的去耦聯作用與麻醉或丘腦失活相同。如果反饋信號主要通過頂端樹突發生，則研究人員發現的細胞機制不僅可以解釋麻醉如何選擇性地阻斷該信號傳導，還可以解釋為什麼有意識的感知同時依賴於皮質-皮質和丘腦-皮質連接。

 

據了解，全身麻醉的奇特之處在於，即使前饋信號和基本神經元功能保持相對不變，它也可以通過破壞大腦中的反饋信號來特異性抑制意識。這種選擇性的機制尚不清楚。

 

附：英文原文

Title: General Anesthesia Decouples Cortical Pyramidal Neurons

Author: Mototaka Suzuki, Matthew E. Larkum

Issue&Volume: 2020/02/20

Abstract: The mystery of general anesthesia is that it specifically suppresses consciousnessby disrupting feedback signaling in the brain, even when feedforward signaling andbasic neuronal function are left relatively unchanged. The mechanism for such selectivenessis unknown. Here we show that three different anesthetics have the same disruptiveinfluence on signaling along apical dendrites in cortical layer 5 pyramidal neuronsin mice. We found that optogenetic depolarization of the distal apical dendrites causedrobust spiking at the cell body under awake conditions that was blocked by anesthesia.Moreover, we found that blocking metabotropic glutamate and cholinergic receptorshad the same effect on apical dendrite decoupling as anesthesia or inactivation ofthe higher-order thalamus. If feedback signaling occurs predominantly through apicaldendrites, the cellular mechanism we found would explain not only how anesthesia selectivelyblocks this signaling but also why conscious perception depends on both cortico-corticaland thalamo-cortical connectivity.

DOI: 10.1016/j.cell.2020.01.024

Source: https://www.cell.com/cell/fulltext/S0092-8674(20)30105-7

Cell：《細胞》，創刊於1974年。隸屬於細胞出版社，最新IF：36.216