Print Close

Layer-specific CBV response characteristics in marmoset primary somatosensory cortex at 7T

Poster No:

1991

Submission Type:

Abstract Submission

Authors:

CHENYU WANG¹, Hirohiko Imai², Masaki Fukunaga³, Hiroki Yamamoto⁴, Yinghua Yu¹, Kazuhiko Seki⁵, Takashi Hanakawa⁶, Tatsuya Umeda⁶, Jiajia Yang¹

Institutions:

¹Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama, Japan, ²Department of Informatics, Kyoto University Graduate School of Informatics, Kyoto, Japan, ³National Institute for Physiological Sciences, Aichi, Japan, ⁴Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan, ⁵Department of Neurophysiology, National Center of Neurology and Psychiatry, Tokyo, Japan, ⁶Department of Integrated Neuroanatomy & Neuroimaging, Kyoto University Graduate School of Medicine, Kyoto, Japan

First Author:

CHENYU WANG
Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University
Okayama, Japan

Co-Author(s):

Hirohiko Imai
Department of Informatics, Kyoto University Graduate School of Informatics
Kyoto, Japan

Masaki Fukunaga
National Institute for Physiological Sciences
Aichi, Japan

Hiroki Yamamoto
Graduate School of Human and Environmental Studies, Kyoto University
Kyoto, Japan

Yinghua Yu
Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University
Okayama, Japan

Kazuhiko Seki
Department of Neurophysiology, National Center of Neurology and Psychiatry
Tokyo, Japan

Takashi Hanakawa
Department of Integrated Neuroanatomy & Neuroimaging, Kyoto University Graduate School of Medicine
Kyoto, Japan

Tatsuya Umeda
Department of Integrated Neuroanatomy & Neuroimaging, Kyoto University Graduate School of Medicine
Kyoto, Japan

Jiajia Yang, Ph.D.
Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University
Okayama, Japan

Introduction:

Common marmosets, a small-bodied New Word primate that shares a similar sensory processing pathway with humans, have gained increasing interest as animal models for investigating the brain mechanisms underlying sensory and cognitive processing. Marmosets' relatively small brain enables the recording of cortical layer-specific activities across the entire brain. Utilizing ultra-high-field functional neuroimaging (fMRI) to investigate marmoset tactile sensory processing provides new insights into layer-specific mechanisms in the primary somatosensory cortex (S1). S1 is known to process tactile information with layer-specific activity patterns (Ann Stringer et al., 2014; Yu et al., 2019); however, the brain response properties at the layer level remain poorly understood.

Methods:

An adult male common marmoset (Callithrix jacchus; aged 7 years old; body weight 340-360g) was used in the present study. All fMRI experiments were performed in a 7T/20-cm bore magnet (Bruker‐Biospin, Billerica, MA, USA). A saddle coil with an inner diameter of 86 mm was used as a transmit coil, and the MR signal was acquired from one loop coil (Takashima Seisakusho Co., Ltd, Tokyo, Japan). On the day of the experiment, initial sedation was induced by a small dose of ketamine (20mg/kg) and isoflurane (2.5%) inhaled via a facemask. After the marmoset received cannulation of a leg vein, anesthesia was switched to a constant intravenous infusion of dexmedetomidine (5ug/kg/hr) and 0.5% isoflurane. A blood oxygenation-level dependent (BOLD) runs and eleven cerebral blood volume (CBV)-weighted runs were acquired before and after injection of 20 mg/kg of 30‐nm ultrasmall superparamagnetic iron oxide (USPIO) particles (Molday ION, Biophysics Assay Laboratory, Inc., USA). BOLD and CBV weighted fMRI datasets were obtained with a gradient echo (GE), echo-planar imaging (EPI) sequence (FOV, 25.875 x 23 mm^2; matrix, 72 x 64; slice thickness, 1 mm; voxel size, 0.36 x 0.36 x 1.0 mm^3; acquisition bandwidth, 250 kHz; TE, (BOLD: 20 ms; CBV-weighted: 10 ms); TR, 2000 ms; flip angle, 60 degrees). We repeated the same task runs across 12 task runs (30s-on 30s-off block design, 200 ms air-puff delivered to right hand during the on blocks). Before each run's stimulation, we added a 3-minute rest period to evaluate the baseline value. Preprocessing of fMRI data, general linear model analysis, and group-level analysis were performed using AFNI. The hand region of interest (ROI) (a green region in Figure 1B) was identified based on the group-level results to calculate the %Signal Change and ΔR2* for each run. Within the hand ROI, upper layer ROI (proximal to the Cerebrospinal Fluid) and deep layer ROI (proximal to the white matter) were defined to compute layer-specific ΔrCBV responses (Zhao et al., 2006). A gamma model was fitted to the ΔrCBV signal during the stimulation period using nonlinear least squares optimization. The study protocol was approved by the experimental animal committee at Kyoto University, Japan.

Results:

Initially, we observed brain activations elicited by right-hand stimulation in the contralateral S1, including area 3b aera 1/2 and area 3a (Clery et al., 2020), as shown in Figure 1B. The U-shape tendency of %Signal Change and ΔR2* (Figure 1C) over time expressed the decay of the contrast agent. Layer-specific ΔrCBV responses (Figure 1D) during hand stimulation were fitted by the gamma model (Upper layer R^2 = 0.757, Deep layer R^2 = 0.704). Deep layers showed a stronger response than the upper layers, emphasizing the differential cortical layer processing mechanism.

·Figure 1

Conclusions:

Initially, we confirmed the marmoset's hand somatosensory areas in S1. Additionally, we successfully recorded and modeled layer-specific tactile stimulation-elicited responses in S1. Our approach is expected to provide new insights into the relationship between layer-specific brain activities and CBV-weighted fMRI signals.

Novel Imaging Acquisition Methods:

Non-BOLD fMRI ¹

Perception, Attention and Motor Behavior:

Perception: Tactile/Somatosensory ²

Keywords:

Cortical Layers

FUNCTIONAL MRI

HIGH FIELD MR

^1|2Indicates the priority used for review

Abstract Information

By submitting your proposal, you grant permission for the Organization for Human Brain Mapping (OHBM) to distribute your work in any format, including video, audio print and electronic text through OHBM OnDemand, social media channels, the OHBM website, or other electronic publications and media.

I accept

The Open Science Special Interest Group (OSSIG) is introducing a reproducibility challenge for OHBM 2025. This new initiative aims to enhance the reproducibility of scientific results and foster collaborations between labs. Teams will consist of a “source” party and a “reproducing” party, and will be evaluated on the success of their replication, the openness of the source work, and additional deliverables. Click here for more information. Propose your OHBM abstract(s) as source work for future OHBM meetings by selecting one of the following options:

I am submitting this abstract as an original work to be reproduced. I am available to be the “source party” in an upcoming team and consent to have this work listed on the OSSIG website. I agree to be contacted by OSSIG regarding the challenge and may share data used in this abstract with another team.

Please indicate below if your study was a "resting state" or "task-activation” study.

Task-activation

Healthy subjects only or patients (note that patient studies may also involve healthy subjects):

Healthy subjects

Was this research conducted in the United States?

Were any human subjects research approved by the relevant Institutional Review Board or ethics panel? NOTE: Any human subjects studies without IRB approval will be automatically rejected.

Were any animal research approved by the relevant IACUC or other animal research panel? NOTE: Any animal studies without IACUC approval will be automatically rejected.

Yes

Please indicate which methods were used in your research:

Functional MRI

For human MRI, what field strength scanner do you use?

Which processing packages did you use for your study?

AFNI

Other, Please list - LayNII

Provide references using APA citation style.

Ann Stringer, E., Qiao, P. G., Friedman, R. M., Holroyd, L., Newton, A. T., Gore, J. C., & Chen, L. M. (2014). Distinct fine-scale fMRI activation patterns of contra- and ipsilateral somatosensory areas 3b and 1 in humans. Human Brain Mapping, 35(9). https://doi.org/10.1002/hbm.22517
Clery, J. C., Hori, Y., Schaeffer, D. J., Gati, J. S., Andrew Pruszynski, J., & Everling, S. (2020). Whole brain mapping of somatosensory responses in awake marmosets investigated with ultra-high-field fMRI. Journal of Neurophysiology, 124(6). https://doi.org/10.1152/jn.00480.2020
Yu, Y., Huber, L., Yang, J., Jangraw, D. C., Handwerker, D. A., Molfese, P. J., Chen, G., Ejima, Y., Wu, J., & Bandettini, P. A. (2019). Layer-specific activation of sensory input and predictive feedback in the human primary somatosensory cortex. http://advances.sciencemag.org/
Zhao, F., Wang, P., Hendrich, K., Ugurbil, K., & Kim, S. G. (2006). Cortical layer-dependent BOLD and CBV responses measured by spin-echo and gradient-echo fMRI: Insights into hemodynamic regulation. NeuroImage, 30(4). https://doi.org/10.1016/j.neuroimage.2005.11.013

UNESCO Institute of Statistics and World Bank Waiver Form

I attest that I currently live, work, or study in a country on the UNESCO Institute of Statistics and World Bank List of Low and Middle Income Countries list provided.