Add Metabolic HH neuron model after Dutta et al.

[bbantal]

Closes #393.

[MasonProtter]

Nice, do you have any tests for this we could put in? I'll add it to the GraphDynamics support list soon.

[bbantal]

Tests are work in progress. Haris suggested I start the PR now though. I'll add tests and once it's ready I'll request a reviewer for the actual pull.

[bbantal]

Added tests and expanded the docstring. Ready for review.

[MasonProtter]

What is this neurontype keyword argument used for? It doesn't seem to affect anything in the code.

[bbantal]

Great catch. Thank you! Somehow the part where it's used got washed out throughout the recent edits. "Neurontype" would be used in the connection rule. See the latest commit which has it now. It would determine whether to use excitatory or inhibitory parameters for the synaptic connection depending on the source neuron's type.

[bbantal]

I did want to ask for some help with this as currently it throws an error and I expect the test to fail accordingly.

ERROR: ArgumentERror: System nrn1: variable neurontype doesn't exist.

I understand where it's coming from, but I'm struggling to find a workaround. Would you have any advice? I think the way it is now used to work in the past but I might be wrong. Either way, is there a way I can access the property neurontype in connections?

[MasonProtter]

Ah I see. It seems that the problem is that @harisorgn added this override for getproperty last month:

Neuroblox.jl/src/blox/blox_utilities.jl

Lines 1 to 9 in 89cadb8

	function Base.getproperty(b::Union{AbstractNeuronBlox, NeuralMassBlox}, name::Symbol)
	# TO DO : Some of the fields below besides `odesystem` and `namespace`
	# are redundant and we should clean them up.
	if (name === :odesystem) || (name === :namespace) || (name === :params) || (name === :output) || (name === :voltage)
	return getfield(b, name)
	else
	return Base.getproperty(Neuroblox.get_namespaced_sys(b), name)
	end
	end

which means that when you do n.field it redirects it to n.system.field instead. Not sure how I feel about that one tbh since it's kinda inconvenient for blox like this.

The fix in your case is simple though, you can just replace

if blox_src.neurontype == "excitatory"

with

if getfield(blox_src, :neurontype) == "excitatory"

---

That said, I think it might be a good idea to have separate types for excitatory versus inhibitory neurons here (or distinguish them by a type parameter like in #532).

If we do want to keep them as one type though, it's usually a little more idiomatic to use a Symbol here instead of a String (i.e. :excitatory instead of "excitatory") but for our purposes here it doesn't really matter much.

[bbantal]

Thanks for the thorough review and for catching these issues @MasonProtter! I have a follow-up question in one of the comments.