I am trying to use this same approach in a new network model, but I am having some trouble. I am trying to record the LFP contribution from a subset of neurons in a network of 800 total neurons. The problem is that the LFP registers action potentials, but not post-synaptic potentials. For instance, I ran a simulation in which I recorded both the intracellular voltage and the LFP from one single neuron in the network. (I recorded the LFP from a single neuron by defining a subset of sections belonging to just that neuron, then passing that subset of sections to a callback using extra_scatter_gather.) The intracellular voltage shows EPSP’s:
![Image](https://i.imgur.com/cgJ0J4d.png)
But the LFP is a perfect flatline (and yes, I checked to make sure there are not small fluctuations when you zoom in):
![Image](https://i.imgur.com/6hsVsMj.png)
But if I increase the strength of excitatory synapses onto this cell, then spikes are elicited:
![Image](https://i.imgur.com/4Oq4xWA.png)
And this does show up in the LFP:
![Image](https://i.imgur.com/n7zIzas.png)
I am at a loss to explain why AP’s register in the LFP, but PSP’s do not. I made a toy simulation with just one neuron, but unfortunately I was unable to replicate the problem (i.e., PSP's did show up in the LFP in the toy simulation).
Any ideas what the problem might be, or how I might troubleshoot this?