Activation-how coupling (AFC) provides a physiological basis for mapping ce
rebral activation using cerebral blood how (CBF) as a surrogate marker for
neuronal function. Laser Doppler offers a minimally invasive approach for m
easuring changes in cerebral blood flow but the spatial resolution of this
technique is limited by the number of individual probes that can be used. R
ecently, laser Doppler imaging (LDI) scanners, which use computer-driven op
tics to scan and measure LD changes in two dimensions, have successfully me
asured how changes in the exposed cortex of animals. Here we demonstrate th
e use of an LDI device through a thinned shall to determine the spatiotempo
ral characteristics of AFC in alpha-chloralose anesthetized rats in respons
e to electrical forepaw stimulation. The spatial and temporal characteristi
cs of the AFC response measured by LDI are in agreement with prior results
obtained using a single LD probe. These results suggest a promising role fo
r LDI in the characterization of the spatiotemporal characteristics of AFC
in animal models and possibly for intraoperative monitoring in the human br
ain. (C) 1999 Academic Press.