The subcellular distribution of T-type Ca2+ channels in LGN interneurons (Allken et al. 2014)

 Download zip file   Auto-launch 
Help downloading and running models
Accession:156039
" ...To study the relationship between the (Ca2+ channel) T-distribution and several (LGN interneuron) IN response properties, we here run a series of simulations where we vary the T-distribution in a multicompartmental IN model with a realistic morphology. We find that the somatic response to somatic current injection is facilitated by a high T-channel density in the soma-region. Conversely, a high T-channel density in the distal dendritic region is found to facilitate dendritic signalling in both the outward direction (increases the response in distal dendrites to somatic input) and the inward direction (the soma responds stronger to distal synaptic input). ..."
Reference:
1 . Allken V, Chepkoech JL, Einevoll GT, Halnes G (2014) The subcellular distribution of T-type Ca2+ channels in interneurons of the lateral geniculate nucleus. PLoS One 9:e107780 [PubMed]
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: Thalamus;
Cell Type(s): Thalamus lateral geniculate nucleus interneuron;
Channel(s): I L high threshold; I T low threshold; I h; I K,Ca; I CAN; I_AHP;
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Dendritic Action Potentials; Active Dendrites; Conductance distributions;
Implementer(s): Allken, Vaneeda [vaneeda at gmail.com];
Search NeuronDB for information about:  I L high threshold; I T low threshold; I h; I K,Ca; I CAN; I_AHP;
TITLE decay of internal calcium concentration
:
: Simple extrusion mechanism for internal calium dynamics
:
: Written by Alain Destexhe, Salk Institute, Nov 12, 1992
: Modified by Geir Halnes, Norwegian Life Science University of Life Sciences, June 2011


INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)}

NEURON {
	SUFFIX Cad
	USEION Ca READ iCa, Cai WRITE Cai VALENCE 2
	RANGE Cainf,taur,k
}

UNITS {
	(molar) = (1/liter)			: moles do not appear in units
	(mM)	= (millimolar)
	(um)	= (micron)
	(mA)	= (milliamp)
	(msM)	= (ms mM)
}


PARAMETER {
	depth	= .1(um)		: depth of shell
	taur	= 50	(ms)		: Zhu et al. used 2 decay terms w/ taus 80ms and 150ms. 1 term 50 ms gives similar decay. 
	Cainf	= 5e-5	(mM)  : Basal Ca-level
	Cainit  = 5e-5 (mM)	: Initial Ca-level
      k       = 0.0155458135   (mmol/C cm)  : Phenomenological constant, estimated to give reasonable intracellular calcium concentration
}


STATE {
	Cai		(mM) <1e-8> : to have tolerance of .01nM
}


INITIAL {
	Cai = Cainit
}


ASSIGNED {
	iCa		(mA/cm2)
	drive_channel	(mM/ms)
	drive_pump	(mM/ms)
}

	
BREAKPOINT {
	SOLVE state METHOD cnexp
}

DERIVATIVE state { 
	drive_channel =  - k * iCa
	if (drive_channel<=0.) { drive_channel = 0. }: cannot pump inward
	Cai' = drive_channel +(Cainf-Cai)/taur
}

Loading data, please wait...