Director of the Department

Prof. Dr. Nikos K. Logothetis
Prof. Dr. Nikos K. Logothetis
nikos.logothetis[at]tuebingen.mpg.de


Secretary: Conchy Moya
Phone: +49 7071 601-651
Fax: +49 7071 601-652
conchy.moya[at]tuebingen.mpg.de
 

Brain Research and Animal Experiments

Information about brain research with animals
 

 

With imaging techniques, such as electroencephalography (EEG), magnetoenzophalography (MEG) or functional magnetic resonance imaging (fMRI) the processes in the brain can be investigated. Brain activity can be recorded even directly or indirectly and interpreted by a computer system.

Ultra High-field MRI systems

Siemens 9.4 whole body system
16.4 T small animal system
9.4 T MR whole body system
In operation since July 2007, this scanner is the third MR system worldwide with this field strength, the first in Europe and the first 9.4 T scanner built by Siemens. The magnet itself weighs 48 tons and the bore diameter is 82 cm without the gradient coil required for spatial encoding. It has a usable bore size of 60 cm and a head gradient with a maximum gradient strength of 60 mT/m and a slew rate of 400 T/m/s. Its length is almost 4 m and it is placed inside a cage consisting of 600 tons of steel for shielding the magnetic field. This scanner is equipped with a broadband amplifier for multi-nuclei excitation. Hardware for excitation and acquisition, like rf-coils and preamplifiers, are designed and built in our institute.
 
16.4 T small animal system
This scanner was delivered in August 2007. With a field strength of 16.4 T and a free bore size of 12 cm, it has the strongest horizontal MR magnet worldwide. The 25 tons magnet with 26 cm bore is accommodated in a 220 tons tempered steel enclosure to shield the stray field. It was built by Magnex Scientific (Oxford, UK), the MR hardware was delivered by Bruker Biospin in Karlsruhe. The system is equipped with gradients with a strength of 1 T/m and a high-performance shim system with dynamic shim capacities. State-of-the-art animal handling and supervision equipment is used to prepare the animals for the experiments, to ensure their well-being during anaesthesia and to monitor their physiological parameters during the measurements.
 

3 Tesla MRI whole body system

Siemens 3T whole body system
A Siemens Tim Trio research system with a magnetic field strength of 3 T and a bore diameter of 60 cm was delivered in July 2006. This scanner is mainly used for functional imaging studies performed by groups of our institute as well as external collaborators. It is capable of signal reception on 32 channels simultaneously for parallel imaging and is equipped with 40mT/m gradients with a slew rate of 200 T/m/s. In addition, the scanner has a secondary broadband amplifier for excitation of nuclei other than protons.

TMS Laboratory

The TMS laboratory is equipped with a Medtronic MagPro X100 stimulator, which is capable of delivering repetitive stimuli up to a rate of 100 Hz as well as paired-pulse stimuli for both mono- and biphasic stimulus waveforms. A custom-made chin rest and a coil holder ensure the stable positioning of the TMS coil at the subject’s head. We use the Fraunhofer Brain View system (Fraunhofer IPA, Stuttgart) for the precise online visualization and tracking of the TMS coil in relation to the subject’s brain. BrainView is a neuronavigation system based on the NDI Polaris optical tracking system. The recording of coil positions for later analysis, time-locked to the application of the TMS pulses, can be triggered by the TMS stimulator. An 8-channel EEG- and MEP-amplifier (Contact Precision Instruments, London, UK) in combination with an A/D conversion card and custom-written software allows for the recording of compound muscle action potentials. Visual and auditory stimuli are presented using Cogent (http://www.vislab.ucl.ac.uk/Cogent) on a PC, which allows us to time-lock the stimulus presentation with the TMS pulses using the PC's serial port. The usage of a MR-compatible TMS coil in combination with a custom-made MR-compatible coil positioning system allows for an online TMS stimulation in the MR scanner while acquiring functional brain images. The precise synchronisation of the TMS pulses with the functional imaging sequence is ensured by using a custom-written C-program.

EEG Laboratory

The QuickAmp 136 (left) is a high input-impedance amplifier capable of measuring and recording up to 128 channels of electroencephalographic (EEG) data, as well as eye (EOG), muscle (EMG) and other physiological signals. It is used for Brain-Computer Interface research, in which brain signals are desired with low noise, high temporal resolution and as high spatial resolution as possible, and where EOG and EMG signals are also required for artefact control. The device is USB-2 compatible, allowing for great flexibility of deployment. It was manufactured and supplied by BrainProducts GmbH as part of a complete system including two 128-channel electrode caps. The manufacturer’s recording software also acts as a server, allowing data to be streamed over TCP/IP with very little delay to our own custom-written analysis software, which is integrated with the de facto standard in online biosignal analysis software, the BCI2000. The hardware is CE-certified as safe for use as a medical device and, in combination with a laptop computer, is highly portable, making it possible for  with patients and paid subjects alike. As of 2008 we have also laboratory that has been optimized for acquiring noise-free EEG signals, using older 40-channel equipment by Precision Instruments, Inc (right).
Last updated: Monday, 16.04.2012