Effect of Isoflurane Anesthesia on BOLD Response to Somatosensory Stimulation: Results from FMRI Experiments in Conscious Rats

Denise Welsh¹, Alexandre Coimbra², Andrew Danziger², Al Rauch², Christopher Regan², Joseph J. Lynch², Donald S. Williams²

Translation of fMRI applications from preclinical to clinical experiments is confounded by the need for anesthesia in animal experiments. Successful implementation of fMRI of sensory stimulation in conscious rats using a combined coil and restraint system, and a pneumatically controlled mechanical stimulation device is described, and cerebral activation following sensory stimulation in awake and anesthestized rats is compared. Hind paw stimulation evoked statistically significant signal intensity increases in the contralateral primary somatosensory cortex of rats in the conscious state, but not in the anesthetized state.