1.2.1 Work Package 1
The intention of WP1 was to develop a PCF-based MRI-compatible Multifunction Probe (MuP), integrating Ca2+ recording, optogenetic stimulation, and fluidic drug microinjection /delivery function. Interactions with scientists from the MPI for the Science of Light, in particular, Dr. Frosz, the MPL have been instrumental in shaping and improving the project. We developed a pure silica MOF-based probe for optogenetically and sensory-driven single-vessel fMRI with simultaneous Ca2+ signals and Mn2+ injection as a proof of concept to optimize the multi-modal fMRI platform, and to make the calcium recording light-path more methodologic and economic friendly for general labs. In 2021 data were presented in zoom-based meetings with the group members and supervisors bi-weekly to ensure regular and sufficient scientific feedback.
1.2.2 Work package 2
The aim of WP2 was to implement the Wireless Amplified NMR Detector (WAND) to enhance fMRI sensitivity with MuP. Here, we first fabricated inductively coupled detectors to provide a unique MRI scheme for in vivo mapping of the local soft tissue to achieve enhanced sensitivity of brain dynamic signals from the local cortex. Then it was combined with simultaneous brain dynamic signal acquisition using optical fiber with high flexibility and practicability. This work package was mainly implemented in the 7T pre-clinical MRI scanner in the Department of Radiology at MSU. In addition, the small animal facilities and animal support team at MSU made it possible for the WP2 for in vivo evaluation in both healthy and diseased animal models.
The manuscript for the methodology development were published as a journal article in NeuroImage.
Chen Y.*; Wang Q.*; Choi S.; Zeng H.; Takahashi K.; Qian C.; Yu X.: Focal fMRI signal enhancement with implantable inductively coupled detectors. NeuroImage 247, 118793, pp. 1-8 (2022). *Equally contributed to this work.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8842502(odnośnik otworzy się w nowym oknie)Moreover, inspired by our work and experimental setup, we also initiated collaboration with Prof. Galit Pelled at MSU to use fMRI to study the novel magnetogenetics stimulation in rats to improve decision-making.
To sum up for the WP2, the project deliverables have mainly been achieved, despite experiencing VISA issue and animal protocol approval issues through the global COVID pandemic in early 2021.
1.2.3 Work package 3
By merging MuP and sensitivity-enhanced fMRI using WAND, these two highly complementary research tools will provide a unique strategy to bridge the gap between cellular/molecular mechanistic studies to the local and whole brain functional mapping level for CC-mediated interhemispheric inhibition in WP3. Since we initiated the experiments before the fellowship was granted and therefore a manuscript without WAND was published as a journal article in 2020. Affected by the pandemic, after careful consideration, we implemented an alternative way to improve the signal sensitivity to answer this question. Thus, we developed a novel bilateral line scanning method to characterize the CC-mediated interhemispheric inhibition with enhanced sensitivity. With this method, we reported that ultra-slow fluctuation (0.01-0.02 Hz) was synchronized across all cortical laminae, and Layer 2/3 specific slow fluctuations (0.08-0.1 Hz). In contrast to the ultra-slow fluctuation related to global brain state changes, the Layer 2/3 specific slow fluctuation is more likely associated with intrinsic neuronal correlation driven by the callosal projection.
The manuscript focused on these results was resubmitted after revisiona and accepted:
Choi S., Zeng H., Chen Y., Sobczak F., Qian C., Yu X.: Laminar-specific functional connectivity mapping with multi-slice line-scanning fMRI. Cerebral Cortex 32(20), pp. 4492-4501 (2022).
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9574235(odnośnik otworzy się w nowym oknie)Now we are performing further data analysis on the data acquired from WP3, we are confident about more scientific output in the coming years.
Brief overview of the results and their exploitation and dissemination:
Conferences attended: 11, of which invited talks: 3
Peer reviewed publications: 2
Posters for conferences: 5
