Hi Sak,

using Ketamine xylazine you will have cortical local field potentials synchronized under slow oscillations, predominantly around delta (1-4 Hz) band. Also, under urethane anesthesia you'll find slow theta (5 Hz) oscillations and respiratory-related rhythms in the hippocampus, for instance.

Hi! There are some works that report the EEG characteristics in rats under ketamine+alpha-2 agonists:

http://www.ncbi.nlm.nih.gov/pubmed/8395591

http://www.ncbi.nlm.nih.gov/pubmed/19470142

Interesting, thanks!

Anesthesia is not sleep. It is different.

I knew that anesthesia is different from sleep, my clarification is that will it interfere in the induced or drug treated animals?

Hi! Also under ketamine/medetomidine you will find similar things, with the advantage that accumulation is better tolerated and heart rate changes are softer. In response of your concrete question, I would say that depends on what drug you are testing. If it is ketamine itself it will interfere for sure. Cheers

Sakthivel, are you studying the effects of those drugs on the EEG or are you studying something else and you want to know if the drugs will interfere?

Hi Sakthivel,

I meant just that you have to take into account that drugs you are testing can compete directly with the mechanisms of anesthesia, such as ketamine, wihich is a non-competitive NMDA antagonist, whith maybe other effects on other receptors.

Hope you get your work ready soon! Regards

My work is that in the field of stress physiology. so i want check what is the difference in the EEG wave pattern recording between control and stress induced animals.

So I don't think any kind of anesthesia will interfere, unless your test drugs directly compete with the receptors of anesthesia -typicaly glutamatergic and gabaergic receptors-. In my opinion ketamine allows a better control of anesthesia depth with a pump or bolus, while urethane is constantly changing its pattern of activiy. In the other hand urethane presents transient states 'similar' to REM sleep. Also, ketamine is reversible, it allows awakening, instead of urethane, where anesthesia cannot be reversed. If you use urethane remember to use gloves, because is a dangerous agent -check details in the internet-. If you work with mice I specially recommend ketamine/medetomidine. Also for rats. Hope this is useful for you! But take into account that mice and rats under anesthesia are not stressed, maybe its better to check it in the awake state. Cheers

I think that if you're doing the exact same doses of anesthetics in both groups, you will be able to compare. Maybe you should try to have the EEG in the animals without anesthesia (although it is often not possible!)

Something that you could do is to record awake during a while and after that anesthetize the animal in order to have both kinds of recordings in 1 day, if awake recordings are possible

Thank you so much to, for your great suggestion and help..

Hello Sak, We studied the effect of subanesthetic acute dose of ketamine 30mg/kg i.p. in rats on qauantittative EEG. Ketamine decreased spectral power in delta and theta, however increased gamma band power. Also discrete decreases in EEG coherences were seen.

In order to eliminate the anestesia effects on EEG we implantate the electrodes in isoflurane anesthesia and rats have one week for recovery before the experiments.

Dear Sakthivel, the following articles will be useful to clarify this issue.

Mechanisms of anesthetic actions and the brain

By: Ishizawa, Yumiko

JOURNAL OF ANESTHESIA Volume: 21 Issue: 2 Pages: 187-199 Published: 2007

A new method for measuring motor evoked potentials in the awake rat: Effects of Anesthetics

By: Oria, Marc; Chatauret, Nicolas; Raguer, Nuria; et al.

JOURNAL OF NEUROTRAUMA Volume: 25 Issue: 3 Pages: 266-275 Published: MAR 2008

Anesthetic effects on electrophysiologic recordings

By: Sloan, TB

JOURNAL OF CLINICAL NEUROPHYSIOLOGY Volume: 15 Issue: 3 Pages: 217-226 Published: MAY 1998