Role of the AIS in the control of spontaneous frequency of dopaminergic neurons (Meza et al 2017)

 Download zip file   Auto-launch 
Help downloading and running models
Computational modeling showed that the size of the Axon Initial Segment (AIS), but not its position within the somatodendritic domain, is the major causal determinant of the tonic firing rate in the intact model, by virtue of the higher intrinsic frequency of the isolated AIS. Further mechanistic analysis of the relationship between neuronal morphology and firing rate showed that dopaminergic neurons function as a coupled oscillator whose frequency of discharge results from a compromise between AIS and somatodendritic oscillators.
1 . Meza RC, López-Jury L, Canavier CC, Henny P (2018) Role of the Axon Initial Segment in the Control of Spontaneous Frequency of Nigral Dopaminergic Neurons In Vivo. J Neurosci 38:733-744 [PubMed]
Citations  Citation Browser
Model Information (Click on a link to find other models with that property)
Model Type: Neuron or other electrically excitable cell;
Brain Region(s)/Organism: Basal ganglia; Mouse;
Cell Type(s): Substantia nigra pars compacta DA cell;
Channel(s): Na/K pump; I K,Ca; I K; I L high threshold; I T low threshold; I A; I N; I Na,t;
Gap Junctions:
Simulation Environment: NEURON;
Model Concept(s): Activity Patterns; Temporal Pattern Generation; Oscillations; Pacemaking mechanism;
Implementer(s): Lopez-Jury, Luciana [lucianalopezjury at]; Canavier, CC;
Search NeuronDB for information about:  Substantia nigra pars compacta DA cell; I Na,t; I L high threshold; I N; I T low threshold; I A; I K; I K,Ca; Na/K pump;
TITLE Calcium ion accumulation without diffusion and buffering
	SUFFIX cabalan
	USEION ca READ cai, ica WRITE cai
	RANGE  cainit, fCa , icapump,icapumpmax,km

	(molar) = (1/liter)
	(mM) =  (millimolar)
	(um) =  (micron)
	(mA) =  (milliamp)
	FARADAY = (faraday) (coulomb) 
	PI = (pi) (1)

         fCa = 0.05  (1)
         cainit = 0.00002 (mM)
        dt    (ms)
        celsius = 35  (degC)
        icapumpmax  = 0.00191  (mA/cm2)
        km = 0.000500         (mM)

	diam  (um)
	ica   (mA/cm2)
          icapump (mA/cm2)

	cai (mM) <1e-10>

	SOLVE state METHOD sparse


KINETIC state {
        icapump = icapumpmax*(1/(1 + km/cai))
	COMPARTMENT PI*diam*diam/4 {cai}
	 ~ cai << (-fCa*(ica +icapump)*PI*diam*(1e4)/(2*FARADAY))