Laminar specificity of functional MRI onset times during somatosensory stimulation in rat.


The blood oxygenation level-dependent (BOLD) response to somatosensory stimulation was measured in alpha-chloralose-anesthetized rats. BOLD fMRI was obtained at 40-ms temporal resolution and spatial resolution of 200 x 200 x 2,000 microm(3) by using a gated activation paradigm in an 11.7 T MRI. Results show a consistent heterogeneity of fMRI onset times and amplitudes. The earliest onset time (0.59 +/- 0.17 s, n = 9) corresponded anatomically to layer IV, with superficial and deeper layers starting significantly later (1.27 +/- 0.43 s in layers I-III, and 1.11 +/- 0.45 s in layer VI). The amplitude of BOLD signal changes also varied with the cortical depth from the pial surface. Changes in the supragranular layers (8.3%) were 44% bigger than changes in the intermediate layers (5.5%), located only approximately 700 microm below, and 144% larger than the bottom layer (3.5%), located approximately 1.4 mm below the pial surface. The data presented demonstrate that BOLD signal changes have distinct amplitude and temporal characteristics, which vary spatially across cortical layers.

7 Figures and Tables

Citations per Year

331 Citations

Semantic Scholar estimates that this publication has 331 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{Silva2002LaminarSO, title={Laminar specificity of functional MRI onset times during somatosensory stimulation in rat.}, author={Afonso C. Silva and Alan P. Koretsky}, journal={Proceedings of the National Academy of Sciences of the United States of America}, year={2002}, volume={99 23}, pages={15182-7} }