Informal Seminar
You have a new invitation for the Informal Seminar on March 7, 2016!

March 7, 2016

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PRESENTING TRISTAN STÖBER

Bernstein Center Freiburg

Monday, 7 March 2016

 

10:00 hours

 

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BCF Library (first floor)
Bernstein Center Freiburg
Hansastraße 9a
79104 Freiburg

 

Hosted by Stefan Rotter

The Relationship between Network Excitability and Medial Temporal Lobe Epilepsy

Medial temporal lobe epilepsy is the most common form of intractable epilepsy and is accompanied by structural changes in and around the hippocampus. Particularly pronounced and well studied are aberrant back-projections of mossy fibers as well as a strong loss of excitatory and inhibitory cells in the hilus of the dentate gyrus. This work studies the effect of a gradual differential cell loss (stronger for inh., weaker for exc. cells) in combination with a subsequent rewiring in a two dimensional, locally connected random network, constructed of 50,000 spiking neurons with conductance based synapses. From a coarse perspective, network dynamics of the lesioned network and the control are comparable. Both exhibit synchronous regular (SR) activity for strong exc. external input and relatively weak inhibition and asynchronous irregular (AI) activity for intermediate levels of exc. input and increased inhibition. But, in the lesion network and for large parts of the respective parameter space, AI activity is frequently interrupted by transient synchronous events, potentially resembling seizure like activity. This is not the case in the control network. There, synchronous events were also found, but are mainly limited to a very narrow transition zone between SR and AI activity. Furthermore, both networks were stimulated with pulse packets at various distances from the lesion/center. It was found, that the lesion network is more susceptible to develop a synchronous event after stimulation and that susceptibility increases with proximity to the lesion site. These findings indicate that structural changes observed in medial temporal lobe epilepsy may destabilize AI activity of the dentate gyrus.

 

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

 


            

BERNSTEIN CENTER FREIBURG
Hansastraße 9a
79104 Freiburg im Breisgau