Brain imaging and brain mapping
State of the art brain imaging techniques are used by NND researchers to study brain structure, activation, connectivity, metabolism and neurotransmitter receptors in health and disease.
A longstanding collaboration exists between HHU and Research Center Jülich with shared facilities dedicated to neuroimaging research including MRI (two 3T human MRI scanner, 3T human MRI-PET hybrid scanner, 9.4T whole body human MRI-PET hybrid scanner, 7T animal MRI scanner, 9.4T animal MRI scanner), Positron emission tomography facilities (ECAT EXACT human PET scanner, high resolution combined PET/CTSPECT animal scanner), 306 channel whole-head MEG, and high density MRI and TMS compatible EEG systems.
A hallmark of neuroimaging research within the NND is a close interaction between basic neuroscience and clinical application. To enable a direct transfer of knowledge from basic research into clinical practice, our work on the physiological organization of the brain is thus always closely linked to clinical questions. Given the complexity of the human brain, this goal will only be attainable by pursuing a multi-modal approach and in particular the integration of complementary information regarding brain structure, function and different aspects of cortical connectivity with cognitive neuropsychology and clinical characterizations.
The group of Orhan Aktas focuses on optical coherence tomography (OCT) to detect specific patterns of inflammatory neurodegeneration in patients. Based on encouraging data in cross-sectional studies with MS patients (Albrecht, J Neurol 2007), this promising method is being further evaluated using latest spectral domain OCT technology (Brandt, Brain 2011 ePub). According to recent data, this method may be useful for longitudinal assessment and follow-up of neuronal damage in both, inflammatory and non-inflammatory neurodegenerative diseases such as multiple sclerosis as well as Parkinson’s disease. This approach allows detection of subtle signs of degeneration in the retinal nerve fibre layer as well as thorough quantitative comparison with defined patient populations.
The research focus of Katrin Amunts and her team is the development of a multi-level and multimodal atlas of the human brain as a tool to integrate the different aspects of brain organization in a common reference space, and to finally understand the principles of brain organization. Her lab is using a wide range of methods, ranging from computer-based analysis of histological preparation, quantitative receptor autoradiography and molecular genetic analyzes, comparative studies, neuroimaging to 3-Polarized Light Imaging to study the architecture of connections (e.g., Amunts and Zilles, Neuron, 2015). The JuBrain cytoviewer and SPM toolbox allow the scientific community to use the microstructural maps as anatomical references for interpreting results of neuroimaging studies. The three-dimensional model of the brain "BigBrain" makes it possible to understand the complex structure of the human brain at a microscopic level in all three directions (BigBrain).
Svenja Caspers has particular expertise in the functional neuroanatomy of micro- and macroscale connectivity in the human brain. She and her group aim at understanding how structural connections are organized in the brain, from large fiber bundles down to single axons. They want to understand how this relates to the functional communication and to individual folding patterns across individuals. For this, they combine microscopic postmortem and modern neuroimaging techniques in-vivo.
A second focus lies on the understanding of the variability of structural and functional connectivity during aging and how this might be explained by environmental and genetic influencing factors. This is studied in large epidemiological cohorts, such as 1000BRAINS and the German National Cohort.
Simon Eickhoff has a longstanding expertise in the multi-modal modeling of brain structure, function and connectivity with a particular focus on the integrated assessment of regional specialization and inter-regional integration. His work focuses on the neural correlates of action control, in particular in the context of reflexive, attentional and volitional control.
A second focus rests on the neuronal correlates of emotional and social decision making in multi-sensory input.
Esther Florin and her group study the electrophysiological basis of fMRI-based functional connectivity (Florin and Baillet 2015). This work involves conducting whole head MEG and EEG measurements and developing and evaluating methods to determine functional and effective connectivity of electrophysiological data (Florin et al., 2010, 2011).
Bettina Pollok and her group studies oscillatory brain networks underlying rhythmic motor behaviour, sensorimotor synchronisation (Pollok, Hum Brain Mapp 2009), and motor performance in highly trained professional musicians (Krause, Neuroimage 2010). Furthermore, she combines non-invasive brain stimulation (using rTMS, tDCs, tACS) with MEG and EEG to modulate brain networks and to study their causal role in the control of motor behaviour (Pollok Eur J Neurosci 2008).
Alfons Schnitzler and his group use neurophysiological approaches such as whole head magnetoencephalography (MEG) and combined MRI/EEG to image and functionally characterize oscillatory brain networks underlying sensory, motor, cognitive and emotional processing in human subjects. Local and long range oscillatory synchronization processes are instrumental for dynamic neuronal communication in the brain (Schnitzler and Gross, Nat Rev Neurosci 2005). Distinct physiological oscillatory brain networks implicated in motor control and attentional processes have been identified in healthy subjects and have been shown to be altered in patients with movement disorders and hepatic encephalopathy. Ongoing projects focus on the role of oscillatory processes in perception (Lange, Cereb Cortex 2011), pain processing (Pollok, PLoS One 2010; Mobascher Hum Brain Mapp 2010; Mobascher, Mol Pain 2010), motor control (Kamp, Age 2011) and visual attention (Kahlbrock, Neuroimage 2011) as well as on analysis methods of cross-frequency coupling (Özkurt, J Neurosci Methods 2011). The cortical representation of action related concepts in another research topic that is persued together with Katja Biermann and funded by the recently established Collaborative Research Centre 991.
In a collaboration with Katrin Amunts from the Research Center Jülich, Alfons Schnitzler and Martin Südmeyer apply longitudinal structural brain imaging to patients with neurodegenerative basal ganglia disorders to delineate disease specific brain atrophy patterns as a biomarker for early early diagnosis and for treatment monitoring. A novel and highly sensitive deformation field morphometry approach has recently been developed by this group (Pieperhoff, Neuroimage 2008). In addition, multimodal molecular imaging is used to enhance diagnostic accuracy in degenerative parkinsonism (Südmeyer, J Nucl Med 2011).