Upcoming IZN Events
 
07.12.2016      13:00

Neurobiology Lecture

 

Imaging structural and molecular dynamics underpinning the embryonic assembly and post-embryonic growth of neural circuits

Jan Felix Elvers
Centre for Organismal Studies (COS),
Heidelberg University,
Heidelberg

Normal nervous system function depends on the formation and maintenance of appropriate synaptic connections and mutations in genes regulating these processes have been identified as causes for cognitive conditions, mental retardation syndromes and neurodegenerative diseases.
This talk will focus on our recent findings of how neuron-neuron interactions and synaptogenesis are coordinated during circuit formation and maturation in the motorsystem of Drosophila.

We show that the presynaptically secreted protein Jelly Belly (Jeb) and its postsynaptic receptor Anaplastic Lymphoma Kinase (Alk) act as trans-synaptic regulator of dendritic growth: downregulation and loss of Alk leads to an increased formation of filopodia-like protrusions, but reduced overall branch complexity of the dendritic arbor; constitutive Alk activation arrests expansion and causes network dysfunction. Unexpectedly, Alk signalling in dendrites is independent of neuro-transmission. Using in vivo time-lapse imaging we find that normal dendritic growth is characterized by exploratory branch extension and retraction in both embryonic and postembryonic development; Jeb-Alk signaling promotes dendritic complexity by upregualting exploratory growth behaviour.

To investigate how synapses mature at the molecular level in the CNS in single identified neurons, we developed techniques that enable us to target proteins at their genomic locus with a conditional fluorescent tag.  We now investigate at the molecular level how synapses emerge and mature between identified pairs of neurons, and how this is coordinated by Jeb-Alk signaling.

 

HS2
Im Neuenheimer Feld 306
Heidelberg

 

Welcome to the IZN Home Page
Selected cells
Kuner T Fig1
Pauen Fig1
Poggi Figure2
Rappold Fig1
Holstein Fig1

In Memoriam

A tribute to Peter H. Seeburg (8.21.1944–8.22.2016)

by Rolf Sprengel, Florian Freudenberg

Seeburg-monoPeter H. Seeburg, a world leader in research on memory and learning, died in Heidelberg on 22 August 2016 at the age of 72. Peter managed to cross several frontiers in biology and opened many new avenues of research. Peter revolutionized fast DNA sequencing, one of the essential prerequisites for the human genome project. He isolated and characterized some of the most important peptide hormones, receptors and ligand-gated ion channels, and he provided the first genetic evidence defining which of these key mediators of cellular communication are critically involved in learning and memory.

In his early days as a postdoc at the University of California in San Francisco, Peter’s great passion was neuroendocrinology. His most important contribution from this part of his career was the cloning of the human growth hormone in 1979. This pioneering work in the cloning of pharmacologically important human proteins was fundamental for the founding of one of the first biotech companies, Genentech. In 1981, together with Joe Messing, Peter established the technology of using bacteriophage M13 for single stranded DNA sequencing. This was a major breakthrough for molecular biology research, and Peter used it extensively in his later research.

In the following years, Peter used his molecular tools, resources and technical skills to unravel the complexity of fast neurotransmission via inhibitory and fast excitatory ion channels in the human brain. Within a few years Peter and his team at the Center for Molecular Biology in Heidelberg (ZMBH) isolated all the subunits of inotropic excitatory and inhibitory receptors of the CNS and characterized them together with Bert Sakmann. He showed that the unexpected complexity of fast neurotransmission is due to multiple genetic factors that co-evolved with the complexity of the brain: many different receptor subunits, several subunit isoforms, pre-mRNA editing and receptor associated proteins.

Peter’s finding of pre-mRNA editing in higher organisms was unexpected – both for him and for the scientific community. But in his paper with Bernd Sommer in Cell, he provided convincing evidence that the single nucleoside difference between mRNA and the corresponding gene sequence of AMPA receptor subunits was not a sequencing artifact but was mediated by an enzyme that Peter was able to isolate in his subsequent experiments. More important still, Peter could show in gene targeted and transgenic mouse models that the epigenetic RNA editing of single nucleosides in the Gria2 pre-mRNA prevents juvenile mice from lethal seizures.

In the last 15–20 years, Peter and his research group, now at the Max Planck Institute for Medical Research in Heidelberg, dedicated themselves to research on learning and memory. They modified or deleted key molecules for synaptic transmission in specific cell types in the mouse brain and described the physiological consequences in very close collaboration with Bert Sakmann’s research group in Heidelberg and Per Andersen’s group in Oslo. Most of the subsequent behavioral analyses of mutant mice were performed by his close collaborators Nick Rawlins and David Bannerman at the University of Oxford. Their findings challenged major dogmas in neuroscience. Peter and his collaborators showed that GluA1 containing AMPA receptors were necessary for short-term spatial working memory but not for long-term spatial reference memory, and that hippocampal NMDA receptors were involved in decision making but not in the storage of spatial maps. Both findings provoked controversial discussions on the function of synaptic plasticity as measured by long-term potentiation of synaptic transmission in learning and memory, and they raised two key questions for neuroscience: whether working memory is necessary for the formation of long-term memory and whether the hippocampus is the storage region for spatial maps. Further studies are necessary to answer these questions. Tragically, Peter will no longer be able to participate as he would have wished. However, his work has already contributed crucially to a major shift in learning and memory research away from the detailed analysis of single synapses and towards the complex analysis of neuronal networks and the communication between different brain areas during learning.

The field of learning and memory research will miss him greatly.

http://www.sciencedirect.com/science/article/pii/S1074742716302957

 

New Regulator of Immune Reaction Discovered

Calcium signal in cell nucleus regulates not only many brain functions but also defence reactions of the immune system

T-lymphozyten
Photo*: Andrea Hellwig
Cells of the immune system can distinguish between protein molecules that are "self" and "non-self". ­For example, if we are exposed to pathogens such as bacteria or viruses that carry foreign molecules on their surface, the body reacts with an immune response. In contrast, cells are "tolerant" of the body's own molecules. This state of unresponsiveness, or anergy, is regulated by a cellular signal, a calcium-controlled switch that was known to control also many brain functions. Neuroscientists from Heidelberg University and immunologists of Heidelberg University Hospital identified this signal. The research results were published in the “Journal of Cell Biology”.

The research work was led by Prof. Dr Hilmar Bading from the Interdisciplinary Center for Neurosciences working together with the research group of Prof. Dr Yvonne Samstag, Director of the Molecular Immunology Section. The Heidelberg research team identified a calcium signal in the cell nucleus of human T lymphocytes as a decision-maker in the immune system. They showed that a nuclear calcium signal is required for the immune reaction that T-cells trigger after contact with molecules foreign to the body.  Externer Inhalt

*Raster electron microscope image of human T lymphocytes

 

Three 'Highly Cited Researchers' at the IZN

Meyer-lindenbergVondeimlingRietschel.jpg
Of the 10 'highly cited researchers' at the Ruperto Carola, 3 are at the IZN: for the third year in succession Professor Drs. Andreas Meyer-Lindenberg and Andreas von Deimling (both Neuroscience & Behavior) and for the first time Prof. Dr. Marcella Rietschel (Psychiatry/Psychology).  Externer Inhalt

 

Prof. Herta Flor honored with John D. Loeser Award

​​​Flor Loeser AwardHerta Flor was honored for her seminal work on learning and memory processes and brain reorganisation in chronic pain and for contributing to the development of novel behaviorally-oriented treatments against chronic pain.

The John D. Loeser Distinguished Lecture Award recognizes Dr. John D. Loeser for his decades of dedication to the promotion of pain education and research. The award is intended to create a tradition that instructs, inspires and challenges clinicians and researchers to understand human pain and the suffering it produces in the broadest ways possible.  Externer Inhalt

 

Seitenanfang

Open positions at the IZN

  • One PhD position is offered in Neurobiology (Prof R. Rudolf Externer Inhalt) to focus on the newly discovered sympathetic co-innervation of vertebrate neuromuscular junctions: development - biomedical relevance - mechanisms of action.  Adobe posted 10.2016
  • Two PhD positions are offered in Developmental Neurobiology (Prof G.E. Pollerberg Externer Inhalt) to focus on new cell adhesion molecule (CAM)-interaction partners which we identified and analyze the functional impact of these interactions on axon growth. The projects are basic research but also aim at contributing to the development of novel therapeutic approaches.  Adobe posted 03.2016

ContactSeitenanfang

Managing Director:
Prof. Dr. Hilmar Bading
IZN-Neurobiology, University of Heidelberg
Im Neuenheimer Feld 364
D-69120 Heidelberg, Germany

Phone:  +49 - 6221 - 54 8218
Fax:  +49 - 6221 - 54 6700
email:  Bading@nbio.uni-heidelberg.de

 

Coordinator:
Dr. Otto Bräunling
IZN-Neurobiology, University of Heidelberg
Im Neuenheimer Feld 364, 1.OG
D-69120 Heidelberg, Germany

Phone:  +49 - 6221 - 54 8694, 56 39007
Fax:  +49 - 6221 - 54 6700
email:  Braeunling@nbio.uni-heidelberg.de

 

Administration & Information:
Irmela Meng
IZN-Neurobiology, University of Heidelberg
Im Neuenheimer Feld 364, 1.OG
D-69120 Heidelberg, Germany

Phone:  +49 - 6221 - 54 8219
Fax:  +49 - 6221 - 54 6700
email:  Sekretariat@nbio.uni-heidelberg.de
Editor: Webmaster
Latest Revision: 2016-12-02
zum Seitenanfang/up