Rapid event-related, BOLD fMRI, non-human primates (NHP): choose two out of three

Joly, Olivier; Pelekanos, Vassilis; Kyriazis, Diana; Mok, Robert M.; Kriegeskorte, Nikolaus; Ainsworth, Matthew; Bell, Andrew H.; Kelly, Maria G.

Abstract

Human functional magnetic resonance imaging (fMRI) typically employs the blood-oxygen-level-dependent (BOLD) contrast mechanism. In non-human primates (NHP), contrast enhancement is possible using monocrystalline iron-oxide nanoparticles (MION) contrast agent, which has a more temporally extended response function. However, using BOLD fMRI in NHP is desirable for interspecies comparison, and the BOLD signal’s faster response function promises to be beneficial for rapid event-related (rER) designs. Here, we used rER BOLD fMRI in macaque monkeys while viewing real-world images, and found visual responses and category selectivity consistent with previous studies. However, activity estimates were very noisy, suggesting that the lower contrast-to-noise ratio of BOLD, suboptimal behavioural performance, and motion artefacts, in combination, render rER BOLD fMRI challenging in NHP. Previous studies have shown that rER fMRI is possible in macaques with MION, despite MION’s prolonged response function. To understand this, we conducted simulations of the BOLD and MION response during rER, and found that no matter how fast the design, the greater amplitude of the MION response outweighs the contrast loss caused by greater temporal smoothing. We conclude that although any two of the three elements (rER, BOLD, NHP) have been shown to work well, the combination of all three is particularly challenging.

Citation

Joly, O., Pelekanos, V., Kyriazis, D., Mok, R. M., Kriegeskorte, N., Ainsworth, M., Bell, A. H., & Kelly, M. G. (2020). Rapid event-related, BOLD fMRI, non-human primates (NHP): choose two out of three. Scientific Reports, 10, Article 7485. https://doi.org/10.1038/s41598-020-64376-8

• Journal Article Type: Article
• Acceptance Date: Apr 15, 2020
• Online Publication Date: May 4, 2020
• Publication Date: 2020
• Deposit Date: May 11, 2020
• Publicly Available Date: May 12, 2020
• Journal: Scientific Reports
• Electronic ISSN: 2045-2322
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 10
• Article Number: 7485
• DOI: https://doi.org/10.1038/s41598-020-64376-8
• Keywords: Multidisciplinary
• Public URL: https://nottingham-repository.worktribe.com/output/4417649
• Publisher URL: https://www.nature.com/articles/s41598-020-64376-8
• Additional Information: Received: 26 September 2019; Accepted: 15 April 2020; First Online: 4 May 2020; : The authors declare no competing interests.