Direct activation of sleep-promoting VLPO neurons by volatile anesthetics contributes to anesthetic hypnosis
Language: 
English
Abstract: 

BACKGROUND: Despite seventeen decades of continuous clinical use, the neuronal mechanisms through which volatile anesthetics act to produce unconsciousness remain obscure. One emerging possibility is that anesthetics exert their hypnotic effects by hijacking endogenous arousal circuits. A key sleep-promoting component of this circuitry is the ventrolateral preoptic nucleus (VLPO), a hypothalamic region containing both state-independent neurons and neurons that preferentially fire during natural sleep. RESULTS: Using c-Fos immunohistochemistry as a biomarker for antecedent neuronal activity, we show that isoflurane and halothane increase the number of active neurons in the VLPO, but only when mice are sedated or unconscious. Destroying VLPO neurons produces an acute resistance to isoflurane-induced hypnosis. Electrophysiological studies prove that the neurons depolarized by isoflurane belong to the subpopulation of VLPO neurons responsible for promoting natural sleep, whereas neighboring non-sleep-active VLPO neurons are unaffected by isoflurane. Finally, we show that this anesthetic-induced depolarization is not solely due to a presynaptic inhibition of wake-active neurons as previously hypothesized but rather is due to a direct postsynaptic effect on VLPO neurons themselves arising from the closing of a background potassium conductance. CONCLUSIONS: Cumulatively, this work demonstrates that anesthetics are capable of directly activating endogenous sleep-promoting networks and that such actions contribute to their hypnotic properties.

Author(s): 
Moore, Jason T.
Chen, Jingqiu
Han, Bo
Meng, Qing Cheng
Veasey, Sigrid C.
Beck, Sheryl G.
Kelz, Max B.
Item Type: 
Journal Article
Publication Title: 
Current biology: CB
Journal Abbreviation: 
Curr. Biol.
Publication Date: 
11/6/2012
Publication Year: 
2012
Pages: 
2008-2016
Volume: 
22
Issue: 
21
ISSN: 
1879-0445
DOI: 
10.1016/j.cub.2012.08.042
Library Catalog: 
PubMed
Extra: 
PMID: 23103189 PMCID: PMC3628836

Turabian/Chicago Citation

Jason T. Moore, Jingqiu Chen, Bo Han, Qing Cheng Meng, Sigrid C. Veasey, Sheryl G. Beck and Max B. Kelz. 11/6/2012. "Direct activation of sleep-promoting VLPO neurons by volatile anesthetics contributes to anesthetic hypnosis." Current biology: CB 22: 21: 2008-2016. 10.1016/j.cub.2012.08.042.

Wikipedia Citation

<ref> {{Cite journal | doi = 10.1016/j.cub.2012.08.042 | issn = 1879-0445 | volume = 22 | pages = 2008-2016 | last = Moore | first = Jason T. | coauthors = Chen, Jingqiu, Han, Bo, Meng, Qing Cheng, Veasey, Sigrid C., Beck, Sheryl G., Kelz, Max B. | title = Direct activation of sleep-promoting VLPO neurons by volatile anesthetics contributes to anesthetic hypnosis | journal = Current biology: CB | date = 11/6/2012 | pmid = | pmc = }} </ref>