Anesthetics are commonly used in preclinical functional MRI studies. It is well-appreciated
that proper choice of anesthetics is of critical importance for maintaining a physiologically
normal range of autonomic functioning. A recent study, using a low dose of
dexmedetomidine (active isomer of medetomidine) in combination with a low dose of
isoflurane, suggested stable measurements across repeated fMRI experiments in individual
animals with each session lasting up to several hours. The rat default mode network has …