UNIVERSITY OF COLOGNE

Sensory feedback about the environment and the body parts generating an animal’s movements are essential for the generation of a coordinated locomotor output of the nervous system (e.g. review in Bidaye et al. 2018). Herein feedback from movement and load sensors on the locomotor organs play a prime role. From previous work in the stick insect walking system it is known, that the generation of a task-specific motor output is assisted by modifications in the processing of sensory feedback in a context-dependent fashion (e.g. Gruhn et al. 2016, Schmitz et al. 2019).

In this PhD project, we aim at investigating
(i) the nature of modifications in the processing of load feedback from leg load sensors (e.g. Zill et al. during different locomotor tasks,
(ii) the contributing mechanisms in the premotor network, and
(iii) their role in the generation of a functional walking motor output. In addition to well-established reduced preparations (e.g. Haberkorn et al. 2019), we will use semi-intact reparations, in which some of the legs, e.g. two front legs, exhibit the specific locomotor behavior, while CS are being stimulated (e.g. Gruhn et al. 2016). Simultaneously, we will record from RetCx and ProCx MNs and their premotor interneurons intracellularly (Rosenbaum et al. 2015).

stick insect (Caurausius Morosus), electrophysiology, intracellular and extracellular recordings, high-speed videotracking of animal movements

Applicants need to hold or be about to complete a M.Sc. degree or equivalent in neurosciences, biological sciences or life sciences. Very good background knowledge in neurobiology, neuroscience and experimental design acquired during master studies is required.

Biday SS, Bockemühl, T. Büschges, A. (2018) Six-legged walking in insects: how CPGs, peripheral feedback, and descending signals generate coordinated and adaptive motor rhythms. J Neurophysiol 119: 459

Gruhn, M., Rosenbaum, P., Bockemühl, T., Büschges, A. (2016) Body Side-specific Control of Motor Activity during Turning in a Walking Animal. eLife 10.7554/eLife.137996

Haberkorn A, Zill SN, Gruhn M, Büschges A (2019) Identification of the Origin of Force Feedback Signals Influencing Motor Neurons of the Thoraco-Coxal Joint in an Insect.
J Comp Physiol A 205(2), 253

Rosenbaum, P., Schmitz, J., Schmidt, J., and Büschges, A. (2015) Task-dependent Modification of Leg Motor Neuron Synaptic Input Underlying Changes in Walking Direction and Walking Speed. Neurophysiol. 114: 1090

Schmitz J, Gruhn M, Büschges A (2019) Body side-specific changes in sensorimotor processing of movement feedback in a walking insect. J Neurophysiol. 2019 Sep 25. doi: 10.1152/jn.00436.2019

Zill. S.N., Schmitz, J., Chaudhry, S. and Büschges, A. (2012) Force encoding in stick insect legs delineates a reference frame for motor control. J. Neurophysiol. 108: 1453
Zill, S.N., Neff, D., Chaudry, S., Exter, A. Schmitz, J, Büschges, A. (2017) Effects of force
detecting sense organs on muscle synergies are correlated with their response properties.
Arthropod, Structure and Development 46: 564