[10+3* Punkte, ausgegeben am 04.05.2005, Abgabe bis 24.05.2005, pdf,
Aufgabe 6: Synchrony of two I&F Neurons
The action potentials of two coupled I&F neuons may synchronize.
In this exercise, you will examine the circumstances under which two
coupled I&F neuons synchronise.
The Matlab program
simulates two I&F neuons which are mutally coupled by two synapses.
It plots the temporal evolution of the membrane potential, the spikes
and the PSCs. You need to unzip the file
into the same directory as sync.m to make sync.m work.
(it contains csim.dll for Windows and csim.mexglx for Linux).
- Do a simulation with the standard parameters. Describe /
explain the result. At which rates1 do the neurons fire?
- Do a simultaion with I1=I2=18. I1 resp. I2 are external currents , which are
injected into the neurons. Describe the results. Why do the neurons
- Do a simultaion with I1=I2=18, w =
30 resp. w=10. Describe the results. Describe the mechanism
that leads to synchronization.
- Do a simultaion with w=30, Tsim=5.0, I1=18 and I2=18.5 respectively I2=22. Tsim
defines the duration of the simulation. Describe / explain the results.
- Make some diagrams (think about well suited diagrams) which
show quantitatively how the quality and speed of synchrony depends on which
parameters. Describe / explain your approach and the results.
- Examine how the results change if you add noise to the
model (set the parameter Inoise ).
Describe / explain the results.
between the PSCs2 and , where
are the averages of and over
and are the considered time interval.
- A well suited measure for the quality of synchronization is the
You can use the time until
is above a
certain value (for a well suited choice of ) as a measure
for the speed of synchronization.
Present your results clearly arranged and document them in a way that
one can reproduce then anytime.
Return a printout ot the Matlab-Code not included insync.m
and which are important to reproduce your results.
- ... rates1
- The vectors st1
and st2 contain all firing times of neuons 1 and 2.
- ... PSCs2
- The PSCs are available in the vectors
Neuronale Netzwerke B (SS05), Rober Legenstein, 2005