White versus gray matter: fMRI hemodynamic responses show similar characteristics, but differ in peak amplitude

BMC Neuroscience

Research Article

M Tynan Stevens¹  Steven D Beyea²  Leanne M Fraser³  Ryan C N D’Arcy⁴ 

[1] National Research Council, Institute for Biodiagnostics (Atlantic), B3H 3A7, Halifax, NS, Canada;Department of Physics and Atmospheric Sciences, Dalhousie University, Halifax, Canada;National Research Council, Institute for Biodiagnostics (Atlantic), B3H 3A7, Halifax, NS, Canada;Department of Physics and Atmospheric Sciences, Dalhousie University, Halifax, Canada;Department of Radiology, Dalhousie University, Halifax, Canada;School of Biomedical Engineering, Dalhousie University, Halifax, Canada;National Research Council, Institute for Biodiagnostics (Atlantic), B3H 3A7, Halifax, NS, Canada;Department of Psychology/Neuroscience, Dalhousie University, Halifax, Canada;National Research Council, Institute for Biodiagnostics (Atlantic), B3H 3A7, Halifax, NS, Canada;Department of Psychology/Neuroscience, Dalhousie University, Halifax, Canada;Department of Radiology, Dalhousie University, Halifax, Canada;Department of Anatomy and Neurobiology, Dalhousie University, Halifax, Canada;

关键词: White matter;    Functional connectivity;    BOLD response;    Hemodynamic response function;    Event-related fMRI;    Interhemispheric transfer;   

DOI  :  10.1186/1471-2202-13-91

 received in 2012-04-02, accepted in 2012-07-17,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundThere is growing evidence for the idea of fMRI activation in white matter. In the current study, we compared hemodynamic response functions (HRF) in white matter and gray matter using 4 T fMRI. White matter fMRI activation was elicited in the isthmus of the corpus callosum at both the group and individual levels (using an established interhemispheric transfer task). Callosal HRFs were compared to HRFs from cingulate and parietal activation.ResultsExamination of the raw HRF revealed similar overall response characteristics. Finite impulse response modeling confirmed that the WM HRF characteristics were comparable to those of the GM HRF, but had significantly decreased peak response amplitudes.ConclusionsOverall, the results matched a priori expectations of smaller HRF responses in white matter due to the relative drop in cerebral blood flow (CBF) and cerebral blood volume (CBV). Importantly, the findings demonstrate that despite lower CBF and CBV, white matter fMRI activation remained within detectable ranges at 4 T.

【 授权许可】

Unknown   
© Fraser et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.