JunProf. Christian Leukel
Sport Science/Human Neurophysiology
April 2017 - January 2018
I am a neurophysiologist investigating neural processes of human motor control and motor learning. I am especially interested in activity and plasticity of the corticospinal system, a phylogenetically higher developed anatomical structure of the nervous system argued to be crucial for controlling and learning skilled behaviour in humans. Further, I am interested in associated information processing between sensory- and motor-related areas of the neocortex (supplementary motor area (SMA), premotor cortex (PC), primary motor cortex (M1)). I specialize in the stimulation techniques transcranial magnetic stimulation (TMS) and peripheral nerve stimulation (PNS), and methods to record neuronal and neuro-muscular activity (electroencephalography (EEG), electromyography (EMG)). In recent projects I have also been using imaging techniques (functional magnetic resonance imaging (fMRI) and position emission tomography (PET)). I often combine neurophysiological stimulation and recording techniques with quantitative analysis of behavior.
Leukel, C., Gollhofer, A., Taube, W. (2015) In Experts, underlying processes that drive visuomotor adaptation are different than in Novices. Front Hum Neurosci, doi: 10.3389/fnhum.2015.00050. (open access - OA)
Leukel, C., Taube, W., Rittweger, J., Gollhofer, A., Ducos, M., Weber, T., Lundbye-Jensen, J. (2015) Changes in corticospinal transmission following 8 weeks of ankle joint immobilization. Clinical Neurophysiology, 126, 131-140.
Taube, W., Mouthon, M., Leukel, C., Hoogewoud, H.M., Annoni, J.M., Keller, M. (2015) Brain activity during observation and motor imagery of different balance tasks: an fMRI study. Cortex, 64, 102-114. (OA)
Taube, W., Leukel, C., Nielsen, J.B., Lundbye-Jensen, J. (2015) Repetitive activation of the corticospinal pathway by means of rTMS may reduce the ef ciency of corticomotoneuronal synapses. Cereb Cortex, 25, 1629 - 1637.
Taube, W., Lundbye-Jensen, J., Schubert, M., Gollhofer, A., Leukel, C. (2011) Evidence that the cortical motor command for the initiation of dynamic plantar exion consists of excitation followed by inhibition. PLoS One, 6, e25657. (OA)
Investigating the corticospinal system in humans
One of the major scientific questions today concerns the functioning of the human brain. A significant problem that slows down scientific progress is the availability of appropriate methods in humans that can provide detailed mechanistic answers similar to what is possible in animal and in in-vitro experiments. In motor neuroscience, a neurophysiological technique called H-reflex conditioning with transcranial magnetic stimulation (TMS) exists, with which the human corticospinal system can be investigated. With this method, synaptic activity and plasticity have been probed for a specific subset of corticospinal connections, namely the fastest (large diameter) monosynaptic corticospinal (pyramidal) projections, which have been proposed to be only present in old world primates and humans. Recent advances with H-reflex conditioning suggest that not only the fastest but also slower conducting corticospinal (pyramidal) projections originating in the primary motor cortex (M1) may be probed. The present project aims to assess to which extent this is possible. Further, in the project it will be tested to which extent other projections originating in premotor areas can be tested by H-reflex conditioning. Finally, existing neurophysiological methods to study cortico-cortical and cortico-spinal projections (short-interval intracortical inhibition - SICI; intracortical facilitation - ICF; premotor-motor conditioning with TMS) will be combined with the H-reflex conditioning technique. The combination with existing methods and the possibility to study also slower pyramidal projections from M1 may lead to new neurophysiological tools with which the corticospinal system in humans can be better investigated in the future.