KBK/KC issue

[pgleeson]

There was a change in the mod file used in the original https://github.com/OpenSourceBrain/SolinasEtAl-GolgiCell model in Neuron in the https://github.com/OpenSourceBrain/SolinasEtAl-GolgiCell/blob/master/NEURON/Golgi_BK.mod channel.

Originally a table was used to calculate the rates:

PROCEDURE rate(v (mV)) {LOCAL a_c, b_c 
	TABLE c_inf, tau_c 
	DEPEND Aalpha_c, Balpha_c, Kalpha_c, 
	       Abeta_c, Bbeta_c, Kbeta_c, celsius FROM -100 TO 30 WITH 13000 
	a_c = alp_c(v)  
	b_c = bet_c(v) 
	tau_c = 1/(a_c + b_c) 
	c_inf = a_c/(a_c + b_c) 
}

However, this was only using the value of [Ca2+] at t=0 in this Ca2+ dependent channel, whereas it should have used the instantaneous value of v and [Ca2+].

This issue was fixed on ModelDB (the TABLE statement removed) and in the current Solinas et al impl here, and the NeuroML 2 impl of this reproduces this behaviour: https://github.com/OpenSourceBrain/SolinasEtAl-GolgiCell/blob/master/NeuroML2/Golgi_KC.channel.nml.

The behavior of the channel was slightly different, and the conductance density of this chan in the solinas cell model was changed to compensate and reproduce the original behaviour

However the original issue propagated to the detailed cell model in this project. This mod file channel was used in the nC version in the 2010 paper, as opposed to the corrected version.

The NeuroML implementation of this cell needs to take this into account, along with other issues such as OpenSourceBrain/SolinasEtAl-GolgiCell#4 and #1.