title: Measurements and modeling of transient blood flow perturbations induced by brief somatosensory stimulation.
abstract: Proper interpretation of BOLD fMRI and other common functional imaging methods requires an understanding of neurovascular coupling. We used laser speckle-contrast optical imaging to measure blood-flow responses in rat somatosensory cortex elicited by brief (2 s) forepaw stimulation. Results show a large increase in local blood flow speed followed by an undershoot and possible late-time oscillations. The blood flow measurements were modeled using the impulse response of a simple linear network, a four-element windkessel. This model yielded excellent fits to the detailed time courses of activated regions. The four-element windkessel model thus provides a simple explanation and interpretation of the transient blood-flow response, both its initial peak and its late-time behavior.
authors.affiliation: Psychology, Neurobiology, Center for Perceptual Systems, Imaging Research Center, The University of Texas at Austin, USA.
authors.forename: Swanul
authors.initials: S
authors.lastname: K
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Dunn
authors.forename: Timothy Q
authors.initials: TQ
authors.lastname: Duong
authors.forename: David
authors.initials: D
authors.lastname: Ress