CORE UNIT PIX: Small animal MRISmall Animal MRI is of today an integral part of biomedical research at highest level. Funding of a 9.4 T small animal MRI system provides the medical faculty of the WWU with the means to overcome a structural disadvantage as compared to other leading universities in biomedical research, which have such systems available. To employ MRI at maximum benefit for the IZKF installation of a core unit (CU) small animal MRI is mandatory. The CU will provide on the one hand the possibility to perform routine scans with high through put for morphological and functional MRI (fMRI). On the other hand it will offer to develop dedicated MR methods for particular needs of the users in order to best exploit the potential of MRI. In particular, the well established MR methodology for tumor and metastasis detection and characterization, for cardiovascular imaging, and fMRI in neurophysiology will be provided. Furthermore, imaging of infection and inflammation will be established as special feature of the IZKF and offer nationally unique possibilities, which will benefit from the installation within an S2 level laboratory and combination of MRI with optical imaging methodology.Imaging networks of the brain by combining multimodal functional imgaging with optogenetic controlIn this project, we will establish a multimodal setup by combining Ca²⁺ recordings and opto-fMRI on a 9.4 T small animal scanner. Ca²⁺ opto-fMRI will be used to investigate the mechanism of neurovascular coupling in naive rats. By optogenetic control, the contributions of individual cell populations (principal excitatory neurons, interneurons, astrocytes) to the hemodynamic response will be broken down.  Stimulation of target cell populations (by optogenetics) and simultaneous direct optical recordings on a millisecond scale (Ca²⁺) and indirect, systemic assessment (BOLD fMRI) of the brain activation will then be used to identify and characterize neuronal networks in the healthy and the epileptic rat brain.