Confirming white matter fMRI activation in the corpus callosum: Co-localization with DTI tractography

Resting-state networks link invasive and noninvasive brain stimulation across diverse psychiatric and neurological diseases

“…S4C). rs-fcMRI clearly is better suited for investigating gray-matter targets; however white matter does contain a small fMRI signal that has been used for activation and rs-fcMRI mapping (105)(106)(107)(108). Future work integrating the complementary strengths of diffusion-based tractography and rs-fcMRI is likely to prove valuable.…”

Functional mapping in the corpus callosum: A 4T fMRI study of white matter

“…This white matter activation is consistent with connections between parietal areas that serve to integrate high level sensory information ( [Witelson, 1989] and [Zarei et al, 2006]). Indeed, we used a subset of the same data to examine diffusion based tractography (Mazerolle et al, 2010). 4 The results linked the white matter activation in the isthmus to gray matter activation in the parietal lobe (Mazerolle et al, 2010).…”

“…Indeed, we used a subset of the same data to examine diffusion based tractography (Mazerolle et al, 2010). 4 The results linked the white matter activation in the isthmus to gray matter activation in the parietal lobe (Mazerolle et al, 2010).…”

“…There are two main reasons for the controversy: 1) BOLD signals rely in part on relatively small fluctuations in cerebral blood volume and flow, which are then 3-6 times lower in white matter ( [Preibisch & Haase, 2001], [Rostrup et al, 2000], [Helenius et al, 2003], [van der Zande et al, 2005] and [Wise et al, 2004]); and 2) the primary source of fMRI signal is thought to arise from post-synaptic potentials (which occur mainly in gray matter) as opposed to action potentials (Logothetis et al, 2001). To put the situation in context, of the 254 287 fMRI studies that have been published to date (according to PubMed at the time this paper was written), there are only nine reporting activation in white matter to our knowledge ( [Tettamanti et al, 2002], [Omura et al, 2004], [Weber et al, 2005], [ and [Mazerolle et al, 2010]). Approximately half of these studies detected white matter activation incidentally.…”

A 9-Year-Old Boy with Multifocal Encephalomalacia: EEG Loreta and Lifespan Database, Magnetic Resonance Imaging and Neuropsychological Agreement

“…This identification may be directly associated with the deficits in the volume of the corpus callosum, such that research shows white matter activation of the isthmus is associated with gray matter activation in parietal lobes. This has important implications for multifunctional integration processes (Gawryluk, D'Arcy, Mazerolle, Brewer, & Beyea, 2010;Mazerolle et al, 2010). Significant deficits in nearly all frequency domains are shown in left parietotemporal regions including auditory cortex and association areas (Heschl's gyrus, transverse=superior temporal gyrus BA 41=42, BA 21=22) in the left hemisphere.…”