The Bernstein Center for Computational Neuroscience Freiburg

Announcement for the next
BCCN Seminar
Anja Gundlfinger
BCCN Berlin

The Hippocampal Mossy Fiber Synapse - Transmission, Modulation and Plasticity

Thursday, September 13, 2007
Lecture Hall (ground floor)
BCCN building
Hansastraße 9A
79104 Freiburg

The mossy fiber synapse onto CA3 pyramidal cells represents a bottleneck of information flow from the dentate gyrus to the cornu ammonis region of the hippocampus. This specialized synapse is highly dynamic in that it shows large and reversible modulation of synaptic strength in response to varying presynaptic stimuli. Hereby, the instantaneous synaptic strength is determined by the recent input, so that it provides a means for coding the temporal input history. One of the determinants of this pronounced short-term plasticity (STP) is an intrinsically low probability of transmitter release at the mossy fiber synapse.
The talk will now focus on two main areas of interest: (1) Presynaptic ionotropic and metabotropic receptor systems tightly control transmitter release as well as plasticity. In this context, I will present recent experimental findings on the cellular signalling cascade by which the neuromodulator adenosine regulates transmission and contributes to the low probability of transmitter release at the hippocampal mossy fiber synapse. (2) Mossy fiber short-term plasticity occurs over an unusually broad temporal range. I will present a computational model capturing the critical parameters of mossy fiber STP based on experimental findings using in vivo like, irregular stimulus paradigms. This model then also provides insight into the consequences of long-term plasticity on the short-term dynamics of transmission at the mossy fiber synapse.

The talk is open to the public. Guests are cordially invited!