Share Email Print

Journal of Biomedical Optics • Open Access

Effects of vasodilation on intrinsic optical signals in the mammalian brain: a phantom study
Author(s): Kandice Tanner; Erin Beitel; Enrico D'Amico; William W. Mantulin; Enrico Gratton

Paper Abstract

Using a broadband spectral technique, we recently showed [J. Biomed. Opt. 10, 064009 (2005)] that during visual stimulation of the cat brain there were not only changes in oxy- and deoxyhemoglobin levels, reminiscent of the optical blood oxygenation level dependence (BOLD) effect reported in humans, but also the apparent water content of the tissue and the optical scattering contribution decreased during stimulation. These relatively fast changes (in seconds) in water tissue content are difficult to explain in physiological terms. We developed a simple model to explain how local vasodilation, which occurs as a result of the stimulation, could cause this apparent change in water content. We show that in a phantom model we can obtain spectral effects similar to those observed in the cat brain such as the apparent decrease of the water spectral component without changing the water content of the bath in which the phantom measurements were performed. Furthermore, using the phantom model, we show that the relative apparent changes in the spectral components due to vasodilation during stimulation are roughly comparable in magnitude to the changes in tissue chromophores due to the optical equivalent of the BOLD effect reported in the literature.

Paper Details

Date Published: 1 November 2006
PDF: 10 pages
J. Biomed. Opt. 11(6) 064020 doi: 10.1117/1.2398920
Published in: Journal of Biomedical Optics Volume 11, Issue 6
Show Author Affiliations
Kandice Tanner, Univ. of California/Irvine (United States)
Erin Beitel, Trinity Univ. (United States)
Enrico D'Amico, Univ. of Illinois at Urbana-Champaign (United States)
William W. Mantulin, Univ. of California/Irvine (United States)
Enrico Gratton, Beckman Laser Institute and Medical Clinic (United States)

© SPIE. Terms of Use
Back to Top