Alexander JS Beckett^1,2, An T Vu^3,4, Sinyeob Ahn⁵, Salvatore Torrisi^1,2, Jonathan R Polimeni^6,7, Essa Yacoub⁸, Kawin Setsampop^9,10, Berkin Bilgic^6,7, Shajan Gunamony^11,12, Andreas Potthast¹³, Peter Dietz¹³, Yulin Chang⁵, and David A Feinberg^1,2
1University of California, Berkeley, CA, United States, ²Advanced MRI Technologies, Sebastopol, CA, United States, ³Radiology, University of California, San Francisco, CA, United States, ⁴San Francisco Veteran Affairs Health Care System, San Francisco, CA, United States, ⁵Siemens Medical Solutions, Malvern, PA, United States, ⁶Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, ⁷Harvard-MIT Health Sciences and Technology, MIT, Cambridge, MA, United States, ⁸Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, ⁹Department of Radiology, Stanford University, Stanford, CA, United States, ¹⁰Department of Electrical Engineering, Stanford University, Stanford, CA, United States, ¹¹Imaging Centre of Excellence, University of Glasgow, Glasgow, United Kingdom, ¹²MR CoilTech Limited, Glasgow, United Kingdom, ¹³Siemens Healthcare GmbH, Erlangen, Germany

The newly developed “Impulse” head gradient (200 mT/m Gmax, 900 T/m/s) on the NexGen 7T scanner has been specifically designed to allow for high-resolution single-shot EPI with minimal distortions and blurring by minimizing echo spacing. In conjunction with the increased SNR and reduced g-factor noise afforded by the 96 channel receive array coil, mesoscale fMRI at 0.45mm and 0.6mm isotropic resolutions can be robustly achieved in human subjects. 

Luisa Raimondo¹, Tomas Knapen^1,2, Serge O Dumoulin^1,2, Wietske van der Zwaag¹, and Jeroen C.W Siero^1,3
1Spinoza Centre for Neuroimaging, Amsterdam, Netherlands, ²VU University, Amsterdam, Netherlands, ³Radiology, University Medical Centre, Utrecht, Netherlands

We implemented spin-echo line-scanning (SELINE) fMRI through a simple rotation of the spin-echo refocusing gradient to a plane perpendicular to the excited slice and removing the phase encode gradient. This technique promises a combination of high spatio-temporal resolution and specificity of functional responses to the microvasculature. We compared SELINE data to the corresponding gradient-echo version (GELINE). We demonstrate that SELINE showed much improved line selection compared to GELINE, albeit at the cost of a significant drop in functional sensitivity. The low functional sensitivity needs to be addressed before SELINE can be applied.

Sebastian Dresbach¹, Renzo Huber¹, and Rainer Goebel^1
1Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, NL, Maastricht, Netherlands

Due to its high specificity, VASO plays a major role in laminar fMRI. To mitigate its lower sensitivity compared to GE-BOLD researchers mostly employ block-designs to increase SNR. Here, we developed a VASO sequence with a short TR (895ms volume acquisition) and showed that it provides the means to capture layer-specific haemodynamic responses with high spatio-temporal resolution. During event-related stimulation, we show reliable responses in visual and somatosensory cortices. Furthermore, the short TR and high specificity of VASO enabled us to show differences in laminar reactivity and onset times, thus demonstrating the high value of event-related designs using CBV-based fMRI.

Kenshu Koiso^1,2, Sebastian Dresbash¹, Christopher J Wiggins³, Omer Faruk Gulban^1,4, Yoichi Miyawaki^2,5, Benedikt A Poser¹, and Renzo Huber^1
1The Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands, ²Graduate School of Informatics and Engineering, The University of Electro-Communications, Tokyo, Japan, ³Scannexus, Maastricht, Netherlands, ⁴Brain Innovation, Maastricht, Netherlands, ⁵Center for Neuroscience and Biomedical Engineering, The University of Electro-Communications, Tokyo, Japan

Laminar-specific fMRI allows neuroscientists to address research questions of directional functional connectivity within and across brain areas. While recent sequence developments allow improvements in coverage and mitigations of venous biases, previous attempts of whole-brain connectome datasets turned out to be too artifact-dominated (Mueller 2021) to be neuroscientifically applicable. Here we present a new and improved sequence used for acquiring a relatively large open dataset of whole-brain laminar connectivity. Its purpose is to:

• investigate the reproducibility of laminar connectivity results, 
• to benchmark and develop processing pipelines, 
• and to explore which type of new neuroscientific research questions become addressable with laminar fMRI.

Duarte Saraiva¹ and Hugo Ferreira^1
1Faculty of Sciences of the University of Lisbon, Lisboa, Portugal

Machine learning (ML) applications on the diagnosis of neuropsychiatric disorders (NPD) have not reached clinical practice yet, as the continuous spectrum of NPD demands more complex, non-binary classification approaches. Herein, a ML-based normative model was created from healthy subjects, which “fails” when tested on schizophrenia patients. In particular, abnormal functional connectivity patterns were found in such patients, in agreement to what has been described in the literature. Moreover, a clustering method and analysis at the individual level indicate that subgroups may exist within the schizophrenia spectrum, suggesting that a personalized and precision-based diagnosis is within reach for such NPD.

Layla Banihashemi¹, Vanessa Jean Schmithorst¹, Michele A Bertocci¹, Alyssa Samolyk¹, Joao Santos¹, Amelia Versace¹, Megan Taylor¹, Gabrielle English¹, Jessie Northrup¹, Vincent Lee¹, Richelle Stiffler¹, Harris Aslam¹, Ashok Panigrahy¹, Alison Hipwell¹, and Mary Phillips^1
1University of Pittsburgh, Pittsburgh, PA, United States

Uncinate fasciculus, forceps minor, and cingulum bundle volumes measured in infants at 3 months of age via DWI tractography were found to predict infant emotionality at 3 months and 9 months of age.  These relations were found to be mediated and/or suppressed by functional connectivity from the orbitofrontal cortex, dorsolateral prefrontal cortex, and posterior default mode.  Therefore, modulating connectivity among regions in the default mode, central executive, and salience networks might be promising future approaches for interventions to maintain infant emotionality and reduce risk of future psychopathology later in childhood and adolescence.

Ingrid Framås Syversen^1,2, Daniel Reznik³, Tobias Navarro Schröder¹, and Christian F. Doeller^1,3,4
1Kavli Institute for Systems Neuroscience, NTNU - Norwegian University of Science and Technology, Trondheim, Norway, ²Department of Diagnostic Imaging, Akershus University Hospital, Lørenskog, Norway, ³Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, ⁴Institute of Psychology, Leipzig University, Leipzig, Germany

Despite previous attempts to localize the human homologues of the medial (MEC) and lateral entorhinal cortex (LEC) using fMRI and DTI separately, there are still uncertainties related to the choice of imaging modality and seed regions used. In this study, we investigated both structural connectivity from DTI and functional connectivity from fMRI between the EC and associated brain regions. Differential EC connectivity to these regions was then used to predict the locations of the human homologues of MEC and LEC. Our results from both DTI and fMRI showed a qualitatively similar subdivision into posteromedial and anterolateral EC, supporting previous studies.

Guocheng Jiang^1,2, Walter Swardfager^2,3, Abdullah Al-Ozairi⁴, Ebaa Al-Ozairi ⁵, Sandra E Black ^2,6, and Bradley J MacIntosh^1,2
1Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, ²Hurvitz Brain Sciences, Sunnybrook Research Institute, Toronto, ON, Canada, ³Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada, ⁴Department of Psychiatry, Kuwait University, Kuwait City, Kuwait, ⁵Dasman Diabetes Institute, Kuwait City, Kuwait, ⁶Department of Medicine, University of Toronto, Toronto, ON, Canada

T2*-weighted image is a versatile and common MR imaging readout. We studied anatomical and functional brain features in three groups: Type 2 diabetes mellitus (T2DM), obese, and healthy adults. We observed that T2DM and obese adults are associated with lower regional T2* relative to healthy adults. We further found that an adverse lipid profile in obese adults was associated with decreased regional brain intrinsic activity. This work helps to characterize how T2DM and obesity affects brain using susceptibility-weighted and resting-state functional MRI approaches.

Frederico Severo¹, Mafalda Valente¹, and Noam Shemesh^1
1Champalimaud Research, Champalimaud Centre for the Unknown, Lisboa, Portugal

Negative BOLD responses (NBRs) in rat Inferior Colliculus (IC) were recently observed upon monaural auditory stimulation, but their origins and importance remain poorly understood. Intercollicular communication is proposed as a prominent mechanism for auditory processing, including sound localization/lateralization & in gain control regulation. Here, we investigated intercollicular interaction via monoaural stimulation at 9.4T. Rats exhibited NBRs in the ipsilateral IC and positive BOLD responses (PBRs) in the contralteral IC. When the contralateral hemisphere was lesioned, the NBRs vanished in the ipsilateral IC. Our findings suggest that intercollicular interaction is essential for ipsilateral negative BOLD responses and for auditory processing.

Julien CAILLETTE¹, Laëtitia Degiorgis¹, Marion Sourty¹, Marion Rame¹, Helin Atas-Ozcan², Laurent Meijer³, Yann Herault², and Laura-Adela Harsan^1,4
1ICube, University of Strasbourg-CNRS, Strasbourg, France, ²IGBMC, University of Strasbourg-CNRS-INSERM, Illkirch-Graffenstaden, France, ³Perha Pharmaceuticals, Perharidy Peninsula, Roscoff, France, ⁴Department of Biophysics and Nuclear Medicine, University Hospital of Strasbourg, Strasbourg, France

DYRK1A protein-kinase overexpression was identified as key player in cognitive impairments observed in Down syndrome (DS) patients and in animal models. Inhibition of this kinase rescued cognitive deficits in the Dp1Yey mouse model of DS, but the associated mechanisms remain unknown. Here we used multimodal brain MRI and characterized the morphology, microstructure and functional connectivity (FC) of Dp1Yey mice. Voxel-based morphometry revealed brain-wide morphological alterations in Dp1Yey mice, while DTI analysis revealed white matter changes. Further, rsfMRI showed that pharmacologic DYRK1A inhibition modifies the functional connectivity for memory related nodes, synergistic with cognitive improvements observed in behavioral tests.

Anirban Sengupta¹, Arabinda Mishra¹, Feng Wang¹, Li Min Chen¹, and John C Gore^1
1Vanderbilt University Medical Center, Nashville, TN, United States

The goal was to study how intrinsic functional networks within squirrel monkey brain undergo changes in connectivity after a dorsal column lesion (DCL) of the spinal cord. We used independent component analysis (ICA) to decompose whole brain fMRI data into spatially independent functional networks. Thirteen networks were identified, many of which resemble networks from human and macaque brain studies. Inter-network connectivity was computed before and after DCL of the cervical spinal cord. Changes in inter-network connectivity were not restricted to sensorimotor areas but spread over other cortical areas. Also, one of the connectivity increased significantly, possibly indicating compensation post lesion

Jiayue Cao¹, Xiaokai Wang¹, and Zhongming Liu^1,2
1Biomedical Engineering, University of Michigan, ANN ARBOR, MI, United States, ²Electrical engineering and computer science, University of Michigan, ANN ARBOR, MI, United States

The default mode network (DMN) is central to cognition. Consistent across species, functional connectivity (FC) of DMN exhibits partly similar patterns across brain states, including wakefulness, sleep, sedated or anesthetized states. Regions in DMN are also involved in regulating visceral organs. It is likely that DMN facilitates visceral physiology to maintain homeostasis in states of unconsciousness. However, the evidence for the association between autonomic function and DMN is sparse and piecemeal. Here, we use fMRI in rat models to investigate how vagal nerve de-innervation and stimulation affect the DMN and its interaction with other regions related to autonomic function.