BOLD
fMRI which relies on neurovascular coupling may fail when neurovascular
coupling is weakened, such as anesthesia or alcohol intoxication. In contrast, diffusion
fMRI has been shown to be more directly linked to neuronal
activation even in the absence of neurovascular coupling. We compared BOLD fMRI
and diffusion fMRI (ADC) time-courses with local field potentials (LFPs) in rat
nucleus accumbens following alcohol stimulation under two different doses of medetomidine
anesthesia. The ADC responses were correlated with LFP signals while BOLD
signals were not. These results show the interest of diffusion fMRI to avoid
confounds from varying conditions of neurovascular coupling.
