Please register and log-in to create and edit pages

User Tools

    Please register and log-in to create and edit pages

Site Tools


Main Menu

Main menu
Click categories to expand


A-Z listingplugin-autotooltip__plain plugin-autotooltip_bigA-Z listing

This is an alphabetical index of all content pages.


Other categories

Utilities

Contacts
Register

Also see

Importance Ratings
News
Legal
Donate/Sponsor


Wikenigma supports:


Feeds etc
rss / xml feed
sitemap file
A-Z listing (archived)


Auto-Translate Site

Wikenigma - an Encyclopedia of Unknowns Wikenigma - an Encyclopedia of the Unknown

General Anaesthetics

A general anaesthetic is a drug that brings about a reversible loss of consciousness. In formal use since 1842 - the first public demonstration used Diethyl ether to carry out surgery. (Though it's likely that alcohol, another chemical classed as an anaesthetic, was previously used, extensively, for similar purposes).

Since then, many other compounds with similar effects have been discovered, and several are now in routine use as general anaesthetics. But the neurological pathways by which general anaesthetics work are still unclear.

“It has always been believed that general anaesthetics exert their effects (analgesia, amnesia, immobility) by modulating the activity of membrane proteins in the neuronal membrane. However, the exact location and mechanism of this action are still largely unknown although much research has been done in this area.”

source: Wikipedia.

An in-depth article by Philip Ball in New Scientist, March 1st 2017 covers the yet-to-be-resolved mysteries surrounding general anaesthetics.

A 2021 study published in the journal Anesthesiology points to a discovery regarding the presence (or lack) of the neurotransmitter acetylcholine in the brain.

Although the precise neural correlates of consciousness have not yet been identified, there is one neurochemical marker that appears to track with our capacity to experience something: acetylcholine concentration in the cerebral cortex. Cortical acetylcholine concentration is high during wakefulness, decreases during slow-wave sleep, and increases again during rapid eye movement sleep, when we can have the conscious experience of dreaming.
Source : Anesthesiology editorial, Feb. 2021

Note regarding Xenon as an anaesthetic

A further anomaly has recently gained attention with regard to xenon. The (extremely inert) gas works efficiently as a general anaesthetic, with low toxicity. It's known to be an NMDA inhibitor but :

“It is not possible to state categorically which […] effects on ligand-gated and receptor-gated ion channels are causally linked to the anaesthetic action of xenon.”

See: Xenon: no stranger to anaesthesia British Journal of Anaesthesia 91 (5)

Given its rarity, xenon is considered prohibitively expensive for medical use - but with the appropriate machinery, it can be recovered (almost 100%) from exhalations.

Importance Rating


    Share this page :

Dear reader : Do you have any suggestions for the site's content?

Ideas for new topics, and suggested additions / corrections for old ones, are always welcome.

If you have skills or interests in a particular field, and have suggestions for Wikenigma, get in touch !


Or, if you'd like to become a regular contributor . . . request a login password. Registered users can edit the entire content of the site, and also create new pages.

( The 'Notes for contributors' section in the main menu has further information and guidelines etc.)

Automatic Translation

You are currently viewing an auto-translated version of Wikenigma

Please be aware that no automatic translation engines are 100% accurate, and so the auto-translated content will very probably feature errors and omissions.

Nevertheless, Wikenigma hopes that the translated content will help to attract a wider global audience.

Show another (random) page

DOKUWIKI IMPLEMENTATION DESIGN BY UNIV.ORG.UK OCTOBER 2021