Talk:General anaesthesia

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    This site aims to review the modeling approach to explain the effects observed in general anesthesia.

    Reviewer 1

    Review of the Scholarpedia article "General anaesthesia" by Axel Hutt, Jamie Sleigh, Alistair Steyn-Ross and Moira l. Steyn-Ross.

    This is a nice and compart review of the mechanisms of general anesthesia. I have a couple of comments to improve the review:

    1. The modeling of anesthesia lacks many important studies, as shown by the very small number of references in the article. In particular the authors should cite the work of Roger Traub, Miles Whittington and colleagues, who studied the role of anaesthetic agents on the fast oscillations (beta and gamma frequency range). They suggested that the action of some anesthetics is to prevent the occurrence of gamma oscillations (Faulkner et al., Brit. J. Pharmacol, 1998). This work includes sophisticated computational models, who predicted that the application of barbiturates change the oscillation frequency by acting on the decay time of GABA_A-mediated currents. This is an important line of work with many published papers, that should be commented and cited.

    2. There are also biophysical models of the effect of anesthesia in the work of Steriade and collaborators, who studied both experimentally and theoretically the effect of barbiturates on Up/Down states, spindle oscillations, delta oscillations, etc. For spindles, one paper was specifically devoted to characterize experimentally and model the difference between natural sleep spindles and barbiturate spindles (Destexhe et al., Neuroscience 1999); the authors showed that the natural sleep spindles were much more synchronous compared to barbiturate spindles. They modeled this effect using thalamocortical networks of spiking neurons, where the barbiturate action was included (in particular on slowing down of GABA_A receptors). This work should also be mentioned.

    There is also the work of Bazhenov, Timofeev, Sejnowski on modeling Up/Down state oscillations, and the effect of anesthetics. Some of this work is summarized in their Scholarpedia article ("Thalamocortical oscillations").


    The paper cites Wikipedia entries but should also consider the Scholarpedia entries. For example the "High-Conductance state" explicitly talks about anesthesia and its effect on up-down state dynamics. Anesthesia is also mentioned in other Sholarpedia papers: Please make links to these papers.

    There is also a "Local Field Potential" Scholarpedia article (in progress), which may be worth linking as well.

    Second Review

    Thank you for making the changes as suggested, I think it is improved. One minor change: the term "small number of neurons" is ambiguous, especially since the aforementioned studies use several hundred of cells, and are meant to model large-scale synchrony. I suggest to change the sentence to "These biophysical models consider networks of up to several hundred neurons." (see my edit in the text)

    If this is fixed, then the paper is ready to be published.

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