Rapid
euthanasia of laboratory rodents without the use of
anesthesia is a necessary research technique whenever there is the likelihood of
anesthesia or stress interfering with the chemistry of the tissues under investigation.
Decapitation has long been the procedure of choice under such circumstances. Recently, however, the American Veterinary Medical Association (AVMA) panel on
euthanasia recommended that
decapitation be avoided on the grounds that the decapitated head may be conscious and suffering for as much as 15 seconds. The panel further recommended that if
decapitation was scientifically necessary, the decapitated head be immediately immersed in liquid
nitrogen. These AVMA guidelines now enjoy regulatory status; the recommendation that
decapitation be avoided has thus caused considerable difficulty for all research requiring rapid,
anesthesia-free collection of tissues. The scientific validity of these recommendations is consequently a matter of great practical as well as theoretical importance. The decision to discourage
decapitation appears to have been based on a single literature report claiming that the EEG of the decapitated head revealed conscious suffering for more than 10 seconds (Mikeska and Klemm 1976). This review carefully examines the scientific literature on this subject. It is concluded that the report by Mikeska and Klemm of EEG activation in the decapitated head is correct, but that this phenomenon is also seen when the decapitated head is under deep
anesthesia, and in normal brains under
ether anesthesia or during REM sleep. Hence these findings do not demonstrate either consciousness or the perception of
pain.(ABSTRACT TRUNCATED AT 250 WORDS)