IMAGING BRAIN ACTIVITY IN CONSCIOUS ANIMALS USING FUNCTIONAL MRI

Functional magnetic resonance imaging (fMRI) in humans has helped impr ove our understanding of the neuroanatomical organization of behavior. Unfortunately, fMRI in animal studies has not kept pace with the huma n work. Experiments are limited because animals must be anesthetized t o prevent motion artifacts, precluding most studies involving neuroima ging of brain activity during behavior. The present study tested a new ly developed head and body holder for performing fMRI in fully conscio us animals. Significant changes in signal intensities were observed in the somatosensory cortex of conscious rats in response to electrical shock of the hindpaw. These changes in evoked signal ranged between 4 and 19% and were accompanied by significant increases in local cerebra l blood flow. The fMRI study was performed with a 2.0-Tesla spectromet er. Using this non-invasive method of imaging brain activity in consci ous animals, it is now possible to perform developmental studies in an imal models of neurological and psychiatric disorders. (C) 1998 Elsevi er Science B.V. All rights reserved.