Joint Annual Meeting ISMRM-ESMRMB 2014 10-16 May 2014 Milan, Italy

Neuroscience Clinical Applications of fMRI

Wednesday 14 May 2014
Space 3  13:30 - 15:30 Moderators: Victoria L. Morgan, Ph.D., Yihoug Yang, Ph.D.

13:30 0577.   Encoding of sound frequency and location in human subcortical structures
Michelle Moerel1, Federico De Martino2, Roberta Santoro2, Kamil Ugurbil1, Essa Yacoub1, and Elia Formisano2
1Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, United States, 2Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands

We combined computational modeling with ultra-high field fMRI (7T) to explore responses to natural sounds in two subcortical auditory structures: the inferior colliculus (IC) and the medial geniculate body (MGB). Out of four computational models tested, only a model with a dependent frequency by location tuning could significantly predict responses to novel testing sounds. This suggests that at the level of IC and MGB, neuronal populations jointly encode sound frequency and sound location. Color-coding voxels according to their best frequency and location revealed fine-grained tonotopic maps and tuning to contralateral sound locations.

13:42 0578.   
Laminar-resolution BOLD and CBV fMRI responding to layer-specific neural modulations in the olfactory bulb
Alexander Poplawsky1, Mitsuhiro Fukuda1, Xiaopeng Zong2, and Seong-Gi Kim1,3
1Radiology, University of Pittsburgh, Pittsburgh, PA, United States, 2Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, NC, United States, 3Biological Sciences, Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), SKKU, Suwon, Korea

We used high-resolution fMRI in the olfactory bulb model to examine whether hemodynamic responses are regulated at the laminar level. Odor and micro-stimulation of the lateral olfactory tract (LOT) were used to preferentially evoke activity in different bulb layers. We found different, neural-specific laminar activation patterns for each individual stimulation using CBV fMRI, but not BOLD. Specifically, for CBV, a ring-like activation was reproducibly observed only in middle layers (~200 µm thick) following LOT stimulation that corresponds with the location of evoked neural activity. Our data provide definitive evidence that the hemodynamic response is regulated at the laminar level.

13:54 0579.   
Top Down Influence on the Visual Cortex of the Blind During Auditory Sensory Substitution
Matthew C. Murphy1,2, Christopher Fisher1, Seong-Gi Kim2,3, Joel S. Schuman1, Amy C. Nau1, and Kevin C. Chan1,2
1Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, United States, 2Neuroimaging Laboratory, Department of Radiology, University of Pittsburgh, Pittsburgh, PA, United States, 3Center for Neuroscience Imaging Research, Department of Biological Sciences, SKKU, Suwon, Korea

Blind persons may acquire visual perception indirectly using sensory substitution devices. One such device (The vOICe) converts images to auditory “soundscapes.” To examine the effect of top down input on the processing of soundscapes in the visual cortex, we scanned sighted and blind subjects both immediately before and immediately after training them to interpret the soundscapes as images. Significant negative BOLD responses were observed in the visual cortex of sighted subjects in both conditions. This negative response is absent in blind subjects before training. Furthermore, the BOLD response becomes significantly positive after training indicating of a significant top down influence.

14:06 0580.   
Optogenetic control of hemodynamic response in rat somatosensory cortex - fMRI and optical study
Bistra Iordanova1, Alberto T Vazquez1, Alex Poplawsky1, Takashi Kozai2, Hiro Fukuda1, Matthew Murphy1, and Seong-Gi Kim1,3
1Dept. of Radiology, University of Pittsburgh, Pittsburgh, PA, United States, 2Dept. of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States, 3Dept. of Biological Sciences, Center for Neuroscience Imaging Research, Suwon, Korea

We use optogenetic approach to modulate the activity of the pyramidal cells in the primary somatosensory cortex. We record hemoglobin-based optical intrinsic signal (OIS) at different light activation parameters. We then compare the OIS to blood oxygenated level dependent (BOLD) fMRI activation.

14:18 0581.   “Domain Gauges”: A Reference System for Multivariate Profiling of Brain fMRI Activation Patterns Induced by Psychoactive Drugs in Rats
Andreas Bruns1, Thomas Mueggler1, Basil Künnecke1, Céline Risterucci1, Joseph G. Wettstein1, and Markus von Kienlin1
1Neuroscience Discovery, F. Hoffmann-La Roche Ltd, Basel, Switzerland

We present “domain gauges” as a set of multivariate metrics to easily quantify and characterize, with only a few numbers, drug-induced brain fMRI activation patterns. The gauges have been calibrated based on different classes (“domains”) of marketed or validated reference drugs. Capitalizing on our in-house database with an unprecedented wealth of standardized rat-brain perfusion fMRI data, we exemplarily defined and applied 3 domain gauges to demonstrate that our approach represents a valuable analytical tool to reveal drug-related neuronal circuits and concisely assess brain activation patterns, thereby facilitating compound characterization and decision making in drug discovery.

14:30 0582.   Distinct BOLD fMRI Responses of Capsaicin-induced Thermal Sensation Reveal Pain-related Brain Activation in Non-Human Primate - permission withheld
Abu Bakar Ali Asad1, Stephanie Seah1, Richard Baumgartner2, Dai Feng2, Andres Jensen1, Brian Henry1, Andrea Houghton3, Jeffrey Evelhoch4, and Chih-Liang Chin1
1Translational Medicine Research Centre, MSD, Singapore, Singapore, 2Biometrics Research, Biostatistics and Research Decision Sciences, Merck & Co Inc, Rahway, New Jersey, United States, 3Neuroscience, Merck & Co Inc, West Point, Pennsylvania, United States, 4Imaging, Merck & Co Inc, West Point, Pennsylvania, United States

To bridge preclinical research and clinical investigation, we established a capsaicin pain heat fMRI model in non-human primate with heat/42 °C stimuli. We hypothesize potentiation in heat-induced cortical activation in response to capsaicin application at the forearm will highlight the ‘pain matrix’ depicted in human pain fMRI experiments. Our results indicate that group comparisons of brain activation between pre- and post-capsaicin application show significant increases in BOLD signals at the frontal, cingulate, precentral and postcentral gyrus, and cerebellum (paired t-test, p<0.002, n=8). Our data provide insights into differentiating brain regions involved with pain-like responses or thermal sensation.

14:42 0583.   Intransal administration of neuroactive peptides elicits robust fMRI responses in the mouse brain
Alberto Galbusera1, Angelo Bifone1, and Alessandro Gozzi1
1MRI Laboratory, Istituto Italiano di Tecnologia, Centre for Neuroscience and Cognitive Sciences, Rovereto, Trento, Italy

Recent studies have highlighted the possibility of exploiting intranasal administration as non invasive method for direct delivery of large therapeutics and neuropeptides to the brain. However, the dynamics and neurofunctional substrates engaged upon intranasal administration of therapeutic agents remain unexplored. We used fMRI in the mouse to characterise the substrates activated by nasal administration of oxytocin and vasopressin, two neuroactive peptides with therapeutic potential. The two peptides elicited robust dicothomic functional responses, with significant cortico-hippocampal activation for oxytocin, and widespread cortical deactivation for vasopressin. These results support the use of fMRI to investigate the functional substrates recruited by intranasally-delivered biologicals.

14:54 0584.   
Subcortical Auditory Information Processing after Bilateral Auditory Cortex Ablation
Patrick P. Gao1,2, Shu-Juan Fan1,2, Jevin W. Zhang1,2, Iris Y. Zhou1,2, Joe S. Cheng1,2, Yuqi Deng2, Dan H. Sanes3, and Ed X. Wu1,2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, HKSAR, China, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, HKSAR, China, 3Department of Biology, New York University, New York, NY, United States

Descending projections from cerebral cortex to subcortical nuclei are among the largest pathways in the brain, suggesting that they are important for subcortical processing. In the auditory system, the cortical output targets multiple subcortical nuclei. However, compared with the ascending pathways, the functional roles of these corticofugal projections are poorly understood. Non-invasive fMRI is well suited to investigating this question because it can assess activities in multiple nuclei simultaneously. In this study, bSSFP fMRI was applied to study the effect of bilateral auditory cortex ablation on the responses to sound pressure level (SPL) change in low subcortical target nuclei.

15:06 0585.   Distinct BOLD laminar profiles elicited by retino-cortical and inter-hemispheric sources in human early visual cortex
Alessio Fracasso1, Natalia Petridou2, and Serge O Dumoulin1
1Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, Netherlands, 2Radiology, Imaging Division, UMC Utrecht, Utrecht, Netherlands

A goal of laminar imaging is to infer the origin of signals by functional laminar profiles. We used a visual paradigm that increases responses in the contralateral hemisphere driven by retino-cortical sources and decreases responses in the ipsilateral hemisphere driven by inter-hemispheric sources. GE-BOLD data were acquired at 0.553mm resolution. Laminar profiles were sorted according to linear trend strength towards the pial surface. Profiles showing a weak linear trend revealed a peak or dip at the middle layers when driven by retino-cortical or inter-hemispheric sources respectively. These profiles demonstrate the ability of laminar imaging to infer the origin of signals.

15:18 0586.   
Functional target localization for neurosurgery: task-based fMRI versus resting state fMRI study
Halleh Ghaderi1,2, Abbas F. Sadikot3,4, and G. Bruce Pike5,6
1Biomedical Engineering, McGill University, Montreal, Quebec, Canada, 2Brain Imaging Center, Montreal Neurological Institute, Montreal, Quebec, Canada, 3Neurology and Neurosurgery, McGill University, Quebec, Canada, 4Brain Imaging Center, Montreal Neurological Institute, Quebec, Canada,5Biomedical Engineering, McGill University, Quebec, Canada, 6Montreal Neurological Institute, Quebec, Canada

This study examines the variability in the location of task-based fMRI activation and compares these results with resting-state fMRI based target localization. The result suggests that using a predefined anatomical atlas coordinates for surgical targeting may not be accurate. But, using a combination of resting-state and task-based fMRI can reliably map somatotopy in the thalamus and somatosensory cortex and hence improve target identification for neurosurgery of deep brain structures.