g = gmax*exp(-t/tau) i = g*(v - e)
This simulation consists of three spike train generators connected to one synapse.
These files are copies of the expsyn example files (along with pregen.mod in nrn/examples/nrniv/netcon. By running
special expsyn.hoc -the example will start with a PointProcessGroupManager that allows you to vary the parameters for the three spike train generators and the synapse. Another panel shows the weight and delay for the three connections.
2) When spikes arrive at the same time, does summation hold?
3) Is it safe to use a Network Connection delay of 0?
4) Compare results with fixed step and global variable time step method. With the variable time step method the default local absolute error tolerance can be obtained by typing
cvode.atolCompare this value with the synapse conductance state g. The absolute local step error tolerance can be changed with
cvode.atol(1e-6)
5) With a spike generator short interval of PI/2 (ms) print the times of the synaptic conductance discontinuities for the fixed and variable time step methods as a function of discontinuity number.
Note: If you pick a Graph line into the vector clipboard, you can then use the Vector methods. Here are examples of some pertinent Vector methods applied to the clipboard:
hoc_obj_.c.printf
hoc_obj_.c.deriv(1,1).printf
hoc_obj_.c.deriv(1,1).indvwhere(">", 1e-5).printf
hoc_obj_.ind(hoc_obj_.c.deriv(1,1).indvwhere(">", 1e-5).add(1)).printf
hoc_obj_[1].ind(hoc_obj_.c.deriv(1,1).indvwhere(">", 1e-5).add(1)).deriv(1,1).printf