I was speaking with our University's vet and she mentioned that live decap is the better route to take if you're planning on doing any histology after death. Does anyone have any further information on this/any sources that show this?
This depends on what type of histology you are doing. The reasoning behind this is that the iso or CO2 can have various effects within the tissues, and the possibility exists that your target will be affected as well. If you are able to do so, live decapitation is probably the best route as it will provide tissue in its most natural state, with no chemicals added. If you would be able to explain the histology you plan on doing (tissues and/or stainings), I may be able to add further insight. I hope this helps and I will search for other references.
We would deeply anesthetize rats with pentobarbital (Nembutol) followed by transcardial perfusion of formalin to fixate brain tissue for visualizing neurons with light or fluorescent microscopy. I agree with previous comment that more details are needed. Although considered ethical for many procedures, I found live decapitation personally disturbing to perform.
Most ethical requirements (from government or institutions) require justification for live decapitation. It depends on what you are measuring- you should look to see if a particular anesthesia is known to have an effect on your measurement, and if that exists it might be worth asking for permission to do live decapitation. But in all likelihood, you won't have permission to do so within your lab's existing ethical permissions (unless someone has asked for it already).
Another point to think about is this- will the stress of the live decapitation affect your measured target more than anesthesia? Acute stress is often a purposeful manipulation and is known to affect many brain parameters, so depending on what you're measuring you might be affecting things more by NOT using anesthesia. Really depends on what you're measuring.
Hi Kristen. Agree with the above comments. Your university or institution must have specific guidelines regarding euthanasia. Ethic committee should revise and approve the project. For hi quality histopathology is best to anesthetize and perfuse, choice of perfusion depends on the project. Overall as indicated above selection of methods depends on what is the objective of the study, and to what extent the experimental animals tissues are going to be used. To reduce number of animals for experimentation we have in the past share tissue collection and adjust the methodology to allow for it. More information will help to get more specific advice.
I agree with many of the answers (especially the Lea Urpa's one).
I just wanted to highlight the fact that in adult rats (using a guillotine) or very young mice and rats (with scissors) the decapitation was favored, depending on what you're measuring. However, it is important to "explain" why this technique is favored over another (e.g., an insufficient training of lungs for CO2 asphyxiation in too young animals).