Informatikkolloquium at the TU Graz with Prof. Dr. Noam Ziv

Dear Colleagues and Students,


it is a pleasure to invite you to the following talks of

Prof. Dr. Noam Ziv from the Technion (Haifa, Israel)


Talk 1 on Thursday, Feb. 9, at 10:45:

Title: “Synaptic tenacity: When everything changes, do things really stay the same?

Talk 2 on Friday, Feb. 10, at 10:45:

Title: “Synaptic Tenacity and Plasticity: The relative contributions of stochastic and directed processes.


Place: Both talk will take place in the Seminar Room of the Institute for Theoretical Computer Science of Graz University of Technology; Inffeldgasse 16b, first floor (IC01074).



Prof. Dr. Wolfgang Maass

Institute for Theoretical Computer Sciences

Graz University of Technology

Inffeldgasse 16b ,   A-8010 Graz,  Austria

Tel.:  ++43/316/873-5822

Fax   ++43/316/873-5805



Abstracts and Scientific Background for these Talks:

“On those stepping into rivers staying the same, other and other waters flow” (Heraclitus)

Activity-dependent modifications to synaptic connections – synaptic plasticity – is widely believed to represent a fundamental mechanism for altering network function. This belief also implies, however, that synapses, when not driven to change their properties by physiologically relevant stimuli, should retain these properties over time. Otherwise, physiologically relevant modifications would be gradually lost amidst spurious changes and spontaneous drift. We refer to the expected tendency of synapses to hold onto their properties as “synaptic tenacity”.

Imaging studies reveal that synapses are not truly structures, and are better thought of   as dynamic assemblies of molecules that move in, out and between synaptic sites over time scales of seconds to hours. These dynamics are associated with very significant fluctuations in synaptic size, and by extension, functional properties. The first talk will focus on synaptic tenacity (or lack thereof) and how size dynamics of individual synapses relate to properties of synaptic populations

Somewhat surprisingly, the (spontaneous) remodeling of individual synapses, as well as features of synaptic populations, such as their shapes and their scaling, are captured remarkably well by statistical models which are essentially stochastic. This raises questions as to relative importance of stochastic processes and specific activity histories in determining the changes synapses undergo. This matter will be the focus of the second talk.

Current affiliation:

Dr. Noam Ziv

Network Biology Research Labs

Fishbach Bldg. Electrical Engineering, Room 419

Technion, Haifa 3200003,