Challenges with Inhibitory Neurons

After finishing playing with excitatory neurons I turned to inhibitory neurons and after several unsuccessful attempts realized that I'll probably spend more time getting them right than I was planning on. Even though I tried many different sets of parameters (based on parameters documented in Izhikevich's book Dynamical Systems in Neuroscience: The Geometry of Excitability and Bursting) I just couldn't get it to work properly. I sent an email to the author, who kindly provided his MATLAB scripts that he used to model fast spiking (FS), late spiking (LS), and thalamic interneurons (TI) neurons. The reason for most of my problems was quite simple: I was using the wrong time step. For example, this is how the diagram looks for similation of one fast spiking (FS) neuron with 0.5ms time step:

and here is how it looks with the correct time step of 0.05ms:

Even though this fixed most of the problems there were still few I didn't know what to do about. For example, the model for thalamic interneurons was unstable with large currents (even with the current just slightly larger than showed in the book: 258pA vs. 255pA):

I also ended up modifying parameters for the low threshold spiking (LTS) neurons; I took c and d parameters from the model for fast spiking neurons (based on the older version of the model). Here is how the result looks like:

And here is the script that I used to generate all these diagrams.

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