Meeting Banner
Abstract #2093

Independent Sources of Spontaneous BOLD Fluctuation Along the Visual Pathway

Jacco A. de Zwart1, Peter van Gelderen1, Zhongming Liu1, Jeff H. Duyn1

1Advanced MRI section, LFMI, NINDS, National Institutes of Health, Bethesda, MD, United States

BOLD fMRI experiments of spontaneous brain activity in humans have found inter-hemispheric correlation between homologous regions, and suggested involvement of a direct callosal connection. We studied spontaneous activity in human Lateral Geniculate Nuclei (LGN), with no direct commissural connections. High-resolution 7 T fMRI was performed during visual stimulation and rest. Correlation analysis was performed between left and right LGN, and left and right visual cortex. Substantial specific left-right LGN correlation was found, which was not merely driven by visual cortex, or the result of global fluctuations. Strong signal coherence was thus found not indicative of a direct neuronal connection.

Keywords

activation activity advanced analyzed apparent approved arise array arrows axial bilateral bold brain channel checkerboard chosen closed cluster coherences coil comparable compromised connection connections consented consisted consistent contribute contribution contributors correlated correlation correlations cortex cortical course cross demonstrating direct discarded downstream either encompassing entirely error even example exceeded excluded exclusion exists explained eyes fibers field finding five fluctuation fluctuations full generally global gradient hand health hemispheric highlight homologous human humans identify independent indicating institutes inter investigate known labeled lack lasted lateral localizer manually marked medical minor national negative neural neuronal nodes noise nuclei open opposite originating paradigm pathway pathways phenomena physiological potential presence previously receive reduction regional registration regressed regression remaining remove respiratory rest resting role scanner section selected series significance simply simulations slices source specificity spontaneous stem strong studied suffered suggested suggesting suggests synchrony system systemic table task thalamus though threshold upstream various versa vice vision visual volunteer volunteers yields