Measurements and Modeling of Transient Blood Flow Perturbations Induced by Brief Somatosensory Stimulation
Reswanul Khan1, 2, Andrew K Dunn3, Timothy Q Duong4, David Ress*, 1
Identifiers and Pagination:Year: 2011
Issue: Suppl 1
First Page: 96
Last Page: 104
Publisher Id: TONIJ-5-96
Article History:Received Date: 19/2/2011
Revision Received Date: 15/3/2011
Acceptance Date: 15/4/2011
Electronic publication date: 4/11/2011
Collection year: 2011
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
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.