Neurowissenschaften / Neuroscience

#28 Cochlea and Auditory Brainstem Physiology

Hauptautor*innen: Christine Köppl

Co-Autor*innen: 

Abstract:

We are broadly interested in the auditory system of vertebrates. The main questions of our research aim to understand mechanisms of sensory encoding and central processing of auditory inputs, as well as developmental regulation of inner-ear development. Our methods include high-resolution microscopy, molecular genetics, classic neurophysiology and optogenetics.

#29 Research Focus of the Neurogenetic Division

Hauptautor*innen: Lena Ebbers

Co-Autor*innen: Maike Claußen, Anna-Maria Hartmann, Friedrich Schinzel

Abstract:

Hearing deficits are the most common sensory disorders in humans. It is estimated that 80% of prelingual hearing loss and more than 50% of age-related hearing loss are due to genetic causes. Our research focuses on the molecular and cellular mechanisms underlying normal and disturbed development of the peripheral and central auditory system. Additionally we are interested in evolutionary processes contributing to the development of the vertebrate auditory system. A second line of research focuses on structure-function analyses to clarify the transport mechanism and functional analysis of human pathogenic variants of the potassium-chloride cotransporter KCC2 that is essential for inhibitory neurotransmission

#30 Evolutionary Development of Excitatory Projection Neurons in Mammalian Sound Localization Circuits

Hauptautor*innen: Denise Krissel

Co-Autor*innen: Dr. Lena Ebbers, Prof. Dr. Hans Gerd Nothwang

Abstract:

Three neuronal populations in the mammalian auditory brainstem enable sound localization: the Dorsal Cochlear Nucleus, the Lateral Superior Olive and the Medial Superior Olive. Fusiform VGluT2-positive excitatory neurons make up the major projection neurons in these populations and simultaneously emerge from the developing hindbrain at embryonic day 10. This study aims to determine the evolutionary and developmental relationship between these subpopulations.
By single nucleus mRNA sequencing of these Vglut2-positive cells the underlying gene regulatory networks are to be reconstructed. To ensure unambiguous identification of the cells of interest the VGluT2::Cre;H2BmCherry mouse line is utilized which expresses the fluorescent histone-bound protein H2BmCherry specifically in all VGluT2-positive cells.
Starting with established, publicly available protocols the procedures were adjusted and scaled to suit our particular needs and to obtain high quality single nuclei of all three neuronal subpopulations.
Many steps of the initial sample processing were adjusted to gain a higher yield or a better quality of nuclei from fresh, unfixed mouse brain tissue; from the preparation of the tissue to dissection, digestion, isolation and storage of the single nuclei towards final protocol modifications to fit size and age of the input material.

#31 Computational Neuroscience

Hauptautor*innen: Jutta Kretzberg

Co-Autor*innen: All members of Division Computational Neuroscience

Abstract:

This poster will give an overview of the main research topics of the computational neuroscience group, centered around sensory processing in nervous systems. Our two main topics are
- Computational models of vertebrate hearing (in the context of hearing4all), in particular directional hearing and effects of aging
- Experiments, data analysis and modeling on the processing of tactile stimuli in the leech. I will focus on the experimental techniques (intracellular electrophysiology, cell staining for anatomical studies, voltage sensitive dye imaging, skin stimulation), which might be interesting for the cooperation with other groups in faculty VI.

#32 Biochemistry

Hauptautor*innen: Karl-Wilhelm Koch

Co-Autor*innen: Alexander Scholten, Maike Möller, Uwe Maschmann

Abstract:

The poster will give an overview of the research projects in the Division of Biochemistry

#33 Cryptochromes as molecular triggers in magnetoreceptive cell responses

Hauptautor*innen: Katharina Görtemaker

Co-Autor*innen: Chad Yee, Karl-Wilhelm Koch

Abstract: Cryptochromes (Crys) are flavin adenine dinucleotide binding proteins that are suggested as the putative magnetoreceptor in migratory birds, because they can host a light-induced radical pair. The most likely candidate so far is Cry4. . Cry4 is expressed in the outer segment of the double cone and the long-wavelength single cone photoreceptor cells in the retina of European robins. After the formation of the radical pair, any downstream signaling pathways are totally unknown. This leads to the question: Which signal transduction cascade connects the radical-pair reaction in Crys to a change in membrane potential? For identifying the potential candidates the yeast-two-hybrid screening (UAS-GAL system) was used. Currently there are eight candidates which are on the short list, focusing on the Long-wavelength opsin and G Protein Subunit Alpha Transducin 2. To examine this suggestion, the heterologous expression of these proteins is necessary. Furthermore, biochemical interaction analysis of erCry4 and the putative interaction partners need to be performed.

#34 Role of RD3 in controlling guanylate cyclase activities in brain

Hauptautor*innen: Yaoyu Chen

Co-Autor*innen: Griesinger F, Woitzik J, Bräuer A.U., Koch K.-W

Abstract:

The RD3 (retinal degenerative protein 3) acts as a crucial regulator of cGMP pathway which paly such functions as phototransduction. We tend to unravel the role of this RD3 lending cGMP pathway to the brain developmental and associating diseases.

#35 The Transition of Photoreceptor Guanylate Cyclase Type 1 to the Active State

Hauptautor*innen: Manisha Kumari Shahu

Co-Autor*innen: Fabian Schuhmann, Alexander Scholten, Ilia A. Solov’yov and Karl-Wilhelm Koch 

Abstract:

Membrane-bound guanylate cyclases (GCs), synthesize the second messenger guanosine-3',5'-cyclic monophosphate, differ in their activation modes to reach the active state. Hormone receptor type guanylate cyclases, for example undergo an ‘α’-helix rotation upon encountering with peptide for activation, but the mechanism of calcium-regulated photoreceptor GCs is unclear. We aim to unravel the conformational switch of photoreceptor guanylate cyclase type 1, GC-E to the active state and compare it with a constitutionally active state, which is found in patients suffering from retinal cone-rod dystrophies. We simulated experimentally an ‘α’-helix rotation by integration of alanine residues close to the transmembrane region by site directed mutagenesis and performed functional studies. We further investigated the enzymatic catalytic parameters of wildtype and the retinal disease-related mutant V902L of GC-E, and characterized the protein dynamics of a conformational switch by a computational approach based on molecular dynamics simulations. Our data shows no involvement of an ‘α’-helix rotation indicating a difference to hormone receptor GCs. The constitutively active state of the V902L mutant is therefore like the active state of wildtype GC-E that is reached by interacting with calcium-sensors. We detected a swinging movement of the dimerization domain in the V902L mutant as the critical conformational switch in...

(Stand: 31.05.2022)