[Comp-neuro] PhD or PostDoctoral Position in Computational Neuroscience of Learning and Memory at the University of Göttingen, Germany

We have a PhD or PostDoc position for a project in Computational Neuroscience of Learning and Memory at the Third Institute of Physics – Biophysics – Georg-August University, Göttingen, Germany

Topic of project: The role of long-term depression during learning and memory formation

At the neuronal network level learning and memory formation are associated with the ability to change synaptic efficiencies (Hebb, 1949). There is an interesting imbalance. On the one side, most of the studies analyze the connection between the increase of synaptic efficiencies (long-term potentiation; LTP) and learning (e.g., Martin et al., 2000). On the other side, the well-known mechanism of synaptic depression (long-term depression; LTD) is in conjunction with learning mainly ignored. Only a few experiments show that LTD is involved in learning and memory dynamics (Manahan-Vaughan and Braunewell, 1999; Whitlock et al., 2006) and even fewer theoretical ideas bring up possible functions of LTD (Willshaw and Dayan, 1990; Miller, 1996). In this project we want to close this gap by augmenting a recent memory model with long-term depression (LTD).

Our current memory model (Tetzlaff et al., 2011; 2012a) is based on a combined adaptation rule of LTP and synaptic scaling (Turrigiano et al., 1998). The combination enables neuronal networks to form local cell assemblies related to “memories” (Tetzlaff et al., 2012b). The goal is to introduce LTD into this model and analyze its functional role (e.g., for the competitive stabilization of cell assemblies). Furthermore, as the reduction in spine size by LTD also induces a shorter synaptic life span (Yasumatsu et al., 2008), the resulting dynamics can be linked to the mechanisms of structural plasticity (Butz et al., 2009).

 

Start date:          01. 07. 2013 (or earlier), negotiable.

Requirements: Theoretical Background (Programming and mathematical analysis of coupled differential equations), Background in Neuroscience.

Salary scale:     German TV-L E13 (50% - 100%, depending on experience).

Our info:             We are part of the Faculty of Physics at the University of Göttingen and the BCCN Göttingen and cooperate closely, e.g., with the Max Planck Institute for Dynamics and Self-Organization and the GGNB Göttingen.

  

Webpage:        http://www.physik3.gwdg.de/cns

 

 

References and further reading about project:

D.O. Hebb (1949). The organization of behavior. Wiley, New York.

S.J. Martin, P.D. Grimwood, and R.G.M. Morris (2000). Synaptic plasticity and memory: an evaluation of the hypothesis. Annu. Rev. Neurosci., 23:649-711.

D. Manahan-Vaughan and K. Braunewell (1999). Novelty acquisition is associated with induction of hippocampal long-term depression. Proc. Natl. Acad. Sci. USA, 96:8739-8744.

J.R. Whitlock, A.J. Heynen, M.G. Shuler, and M.F. Bear (2006). Learning induces long-term potentiation in the hippocampus. Science, 313:1093-1097.

D.J. Willshaw and P. Dayan (1990). Optimal plasticity from matrix memories: what goes up must come down. Neural Comput., 2:85:93.

K.D.  Miller (1996). Synaptic economics: competition and cooperation in synaptic plasticity. Neuron, 17:371-374.

C. Tetzlaff, C. Kolodziejski, M. Timme, and F. Wörgötter (2011). Synaptic scaling in combination with many generic plasticity mechanisms stabilizes circuit connectivity. Fron. Comput. Neurosci., 5:47.

C. Tetzlaff, C. Kolodziejski, M. Timme, and F. Wörgötter (2012a). Analysis of synaptic scaling in combination with Hebbian plasticity in several simple networks. Front. Comput. Neurosci., 6:36.

 G.G. Turrigiano, K.R. Leslie, N.S. Desai, L.C. Rutherford, and S.B. Nelson (1998). Activity-dependent scaling of quantal amplitude in neocortical neurons. Nature, 391:892-896.

 C. Tetzlaff, C. Kolodziejski, M. Timme, M. Tsodyks, and F. Wörgötter (2012b). Memory formation, recall and forgetting in neuronal networks. Front. Comput. Neurosci. Conference Abstract: Bernstein Conference 2012. doi: 10.3389/conf.fncom.2012.55.00225.

 N. Yasumatsu, M. Matsuzaki, T. Miyazaki, J. Noguchi, and H. Kasai (2008). Principles of long-term dynamics of dendritic spines. J. Neurosci., 28:13592-13608.

 M. Butz, F. Wörgötter, and A. Van Ooyen (2009). Activity-dependent structural plasticity. Brain Res. Rev., 60:287-305.

 

 

 

Please send applications (PDF only) to, or request further information from:

  

 

 Christian Tetzlaff (tetzlaff@physik3.gwdg.de) or

 Florentin Wörgötter (worgott@physik3.gwdg.de)