fMRI of visual system activation in the conscious rabbit.

A conscious rabbit preparation developed for fMRI, and the results from visual stimulation studies at a 4.7T magnetic field are described. The rabbit is ideal for these experiments because of its natural tolerance for restraint. High spatial and temporal resolution magnetic resonance images, without movement artifacts, were obtained during long periods of restraint. Functional activation in primary visual cortex and lateral geniculate nucleus (LGN) were reproducibly observed in response to light stimulus. In comparison to existing anesthetized animal models, a functional response free of the anesthetic modulation can be recorded with the new approach. The conscious animal model can be applied to functional studies of sensory systems, learning and memory, and drug-induced cerebral activation.