On the role of anesthesia on the body/brain temperature differential in rats

Different anesthetics often produce distinctly different effects on blood flow, oxygen consumption and other physiological parameters in animal studies. We investigated the influence of two common anesthetics-alpha-chloralose and chloral hydrate-on the body-core/brain temperature differential in rats. The results indicate a remarkable difference of 4.34 +/- 0.64 degreesC (mean +/- SD) in the body-core/brain-cortical temperature differential observed under alpha-chloralose anesthesia compared to a relatively smaller differential of 2.73 +/- 0.40 degreesC under chloral hydrate anesthesia in rats. Temperature gradients within the brain are around 0.3 degreesC/mm in both cases. Thus, the anesthetic utilized has the potential to markedly influence brain temperature and therefore other important physiological parameters in the brain. (C) 2004 Elsevier Ltd. All rights reserved.