In 2007, the CIN started with 25 principal investigators as cluster applicants, as stipulated in the DFG call for bids. When the CIN cluster was approved further scientists from a range of institutions were incorporated, to make up the 48 'founding members' of the CIN. Since the beginning of 2014 the CIN has consisted of over 80 scientists in total. The membership process involves an application to the steering committee in which the candidate outlines his or her scientific profile and submits a list of publications. The committee's decision is based purely on the scientific excellence of each candidate.
Prof. Dr. Ulf Ziemann
Field of Research
The primary motor cortex is crucial for execution of movements. It is connected with a distributed network of associative motor and sensory areas. Coordinated neuronal activity in this network is fundamental for self-initiated and cued movements. Lesions and/or alterations in the functional and effective connectivity in this network (e.g. after cerebral stroke or in multiple sclerosis, or in movement disorders such as dystonia or Parkinson’s disease) may result in paresis or disruption of coordinated movements (Kang et al., 2011; Wahl et al., 2011).
Pharmacological modulation of connectivity, plasticity and learning in motor circuits
Effective synaptic connectivity, plasticity and learning can be significantly modulated by pharmacological stimulation (CNS active drugs) (Korchounov and Ziemann, 2011) or non-invasive transcranial brain stimulation (Arai et al., 2011). One important aim of our group is specific modification of selected projections in the motor network, such as the connection from supplementary motor area to primary motor cortex. This connection is of crucial importance for self-initiated movements and for recovery of motor performance after stroke. Specific connectivity modification will be achieved by spike-timing dependent-like plasticity induced by novel MRI-guided paired and multiple-coil TMS techniques. Functional MRI, EEG or MEG and behavioral measures of motor performance are used to assess changes in functional or effective connectivity. Advances in this understanding in healthy subjects are subsequently applied to patients with neurological conditions such as stroke or movement disorders in attempts to enhance neurorehabilitative processes or alleviate motor discoordination.
Development of biomarkers for assessment of connectivity in motor circuits
Combining TMS and EEG allows direct recording of the propagation of TMS effects in cortical networks (Bruckmann et al., 2012). We will systematically test the effects of a large variety of CNS active drugs on TMS evoked EEG potentials to develop new non-invasive and easy to record biomarkers for changes in resting state cortico-cortical effective connectivity. Advances in the pharmacological and physiological characterization of TMS-EEG will be applied to study disconnection disorders, such as multiple sclerosis and schizophrenia.
Predictors and determinants of plasticity in motor circuits
The ability to induce plasticity with non-invasive brain stimulation techniques in motor circuits of human cortex has driven a large number of recent studies examining whether it might be possible to induce functionally significant plasticity in neurological and psychiatric patients. However, even in healthy subjects the variability in the response to non-invasive brain stimulation techniques is high (Ridding and Ziemann, 2010). The reasons for this interindividual variability are only incompletely understood. Our group will systematically explore predictors and determinants of this plasticity in motor circuits by testing SNPs of regulator molecules of neuronal excitability, synaptic neurotransmission and plasticity, and baseline neurophysiological characteristics of the motor circuit. Advances of knowledge in this field will have profound impact on prediction of neurorehabilitative capacity in stroke patients.
The focus of our laboratory is to explore excitability, connectivity, plasticity and reorganization of these motor circuits in health and disease at the systems level by using structural and functional MRI, MEG, EEG, transcranial magnetic and direct current stimulation (TMS, tDCS), near infrared spectroscopy (NIRS) and combinations of these techniques.
Arai, N., Müller-Dahlhaus, F., Murakami, T., Bliem, B., Lu, M.K., Ugawa, Y., and Ziemann, U. (2011). State-Dependent and Timing-Dependent Bidirectional Associative Plasticity in the Human SMA-M1 Network. J Neurosci 31, 15376-15383.
Bruckmann, S., Hauk, D., Roessner, V., Resch, F., Freitag, C.M., Kammer, T., Ziemann, U., Rothenberger, A., Weisbrod, M., and Bender, S. (2012). Cortical inhibition in attention deficit hyperactivity disorder: new insights from the electroencephalographic response to transcranial magnetic stimulation. Brain 135, 2215-2230.
Kang, J.-S., Terranova, C., Hilker, R., Quartarone, A., and Ziemann, U. (2011). Deficient homeostatic regulation of practice-dependent plasticity in writer’s cramp. Cereb Cortex 21, 1203-1212.
Korchounov, A., and Ziemann, U. (2011). Neuromodulatory Neurotransmitters Influence LTP-Like Plasticity in Human Cortex: A Pharmaco-TMS Study. Neuropsychopharmacology 36, 1894-1902.
Ridding, M.C., and Ziemann, U. (2010). Determinants of the induction of cortical plasticity by non-invasive brain stimulation in healthy subjects. J Physiol 588, 2291–2304.
Wahl, M., Hübers, A., Lauterbach-Soon, B., Hattingen, E., Jung, P., Cohen, L.G., and Ziemann, U. (2011). Motor callosal disconnection in early relapsing-remitting multiple sclerosis. Hum Brain Map 32, 846-855.