Title
Layer-specific BOLD activation in awake monkey V1 revealed by ultra-high spatial resolution functional magnetic resonance imaging.
Abstract
The laminar structure of the cortex has previously been explored both in non-human primates and human subjects using high-resolution functional magnetic resonance imaging (fMRI). However, whether the spatial specificity of the blood-oxygenation-level-dependent (BOLD) fMRI is sufficiently high to reveal lamina specific organization in the cortex reliably is still unclear. In this study we demonstrate for the first time the detection of such layer-specific activation in awake monkeys at the spatial resolution of 200×200×1000μm3 in a vertical 4.7T scanner. Results collected in trained monkeys are high in contrast-to-noise ratio and low in motion artifacts. Isolation of laminar activation was aided by choosing the optimal slice orientation and thickness using a novel pial vein pattern analysis derived from optical imaging. We found that the percent change of GE-BOLD signal is the highest at a depth corresponding to layer IV. Changes in the middle layers (layer IV) were 30% greater than changes in the top layers (layers I–III), and 32% greater than the bottom layers (layers V/VI). The laminar distribution of BOLD signal correlates well with neural activity reported in the literature. Our results suggest that the high intrinsic spatial resolution of GE-BOLD signal is sufficient for mapping sub-millimeter functional structures in awake monkeys. This degree of spatial specificity will be useful for mapping both laminar activations and columnar structures in the cerebral cortex.
Year
DOI
Venue
2013
10.1016/j.neuroimage.2012.08.060
NeuroImage
Keywords
DocType
Volume
BOLD spatial resolution,Cortical layers,Functional MRI,Non-human primate,Visual cortex
Journal
64
ISSN
Citations 
PageRank 
1053-8119
2
0.40
References 
Authors
0
4
Name
Order
Citations
PageRank
Gang Chen1121.82
Feng Wang2387.16
John C Gore361641.36
Anna W. Roe4264.88