Comparing BOLD fMRI signal changes in the awake and anesthetized rat during electrical forepaw stimulation

The difference between awake curarized and alpha -chloralise anesthetized animals was studied with respect to the BOLD signal response in an fMRI experiment. By studying the activation of the cortex upon electrical forepaw stimulation in the same rat. but following consecutively applied curarization and alpha -chloralose anesthesia protocols, it was possible to compare quantitatively the effect of both immobilization protocols on the fMRI data. The largest BOLD signal change as a result of forepaw stimulation was found in the awake condition, however the activated areas are less specific than those in the anesthetized state leaving it more difficult to interpret. (C) 2001 Elsevier Science Inc. All rights reserved.