Calcium spikes in basal dendrites (Kampa and Stuart 2006)

 Download zip file   Auto-launch 
Help downloading and running models
Accession:108458
This model was published in Kampa & Stuart (2006) J Neurosci 26(28):7424-32. The simulation creates two plots showing voltage and calcium changes in basal dendrites of layer 5 pyramidal neurons during action potential backpropagation. created by B. Kampa (2006)
Reference:
1 . Kampa BM, Stuart GJ (2006) Calcium spikes in basal dendrites of layer 5 pyramidal neurons during action potential bursts. J Neurosci 26:7424-32 [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:
Cell Type(s): Neocortex U1 L5B pyramidal pyramidal tract GLU cell;
Channel(s): I L high threshold; I T low threshold; I A; I Sodium; I Potassium;
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Dendritic Action Potentials; Active Dendrites; Action Potentials; Synaptic Integration; Calcium dynamics;
Implementer(s): Kampa, Bjorn M [Bjoern.Kampa at anu.edu.au];
Search NeuronDB for information about:  Neocortex U1 L5B pyramidal pyramidal tract GLU cell; I L high threshold; I T low threshold; I A; I Sodium; I Potassium;
// initialize user-defined membrane parameters 
// use mechanisms na, kv, ka, cad, ca, it
// active conductances from Schaefer et al 2003
//
// by B.Kampa 2006

proc init_params() {
		celsius=35
		Ri=150    
		Cm=1     
		Rm=15000 
		v_init = -65 	 	// RMP -81 mV under ZD 7288 
		spinescale=2.0  		// scale total area to account for spines 
		hblock=0			// fraction of h current blocked by ZD 7288 
		hfactor = 0.00010144 	// for 2.5 mM K+
		hinvtau = 0.0041  	// for 2.5 mM K+
}


//-------------------------------------------------------------------------
// initalise passive properties and add spines by scaling Rm and Cm, NOT scaled for spines: axon, soma, 1st 100 um of apical dend, the 1st 20 um of basals 
//----------------------------------------------------------------------

proc init_spine() {
	forall {insert pas g_pas=1/(Rm/spinescale) cm=Cm*spinescale Ra=Ri 
}

axon {g_pas=0.02 }
soma {g_pas=1/Rm cm=Cm}

	 for i=0,14 {
		 dend1[i]  {g_pas=1/Rm cm=Cm}
	 }
	 for i=15,27 {
		 dend1[i]  {g_pas=1/Rm cm=Cm}
	 }
	 for i=28,32 {
		 dend1[i]  {g_pas=1/Rm cm=Cm}
	 }
	 for i=43,47 {
		 dend1[i]  {g_pas=1/Rm cm=Cm}
	 }
	 for i=71,72 {
		 dend1[i]  {g_pas=1/Rm cm=Cm}
	 }
	 for i=777,778 {
		 dend1[i]  {g_pas=1/Rm cm=Cm}2
	 }
 	for i=808,810 {
		 dend1[i]  {g_pas=1/Rm cm=Cm}
	 }
	 for i=923,924 {
		 dend1[i]  {g_pas=1/Rm cm=Cm}
	 }
	 for i=957,959 {
		 dend1[i]  {g_pas=1/Rm cm=Cm}
	 }
	 for i=1006,1007 {
		 dend1[i]  {g_pas=1/Rm cm=Cm}
	 }
	 for i=1055,1058 {
		 dend1[i]  {g_pas=1/Rm cm=Cm}
	 }
	 for i=1059,1060 {
		 dend1[i]  {g_pas=1/Rm cm=Cm}
	 }
	 for i=1067,1069 {
		 dend1[i]  {g_pas=1/Rm cm=Cm}
	 }
}

//--------------------------------------------------
// initialise nonunifrom resting Vm
//----------------------------------------------------

proc init_vm() { 
	forall {
		e_pas=v_init
	}
	access dend1[21]
	distance()

	for i=0,1090 {
	dend1[i] {e_pas=v_init+(0.011*(distance(.5)))
		}
	}
}

//-------------------------------------------------
// Insert active mod.mechanisms
// --------------------------------------------------

proc init_cell() {

gna_dend 	= 30		*spinescale 
gna_node 	= 30000   
gna_soma 	= 30
 
gkv_axon 	= 30	
gkv_soma 	= 30 	
gkv_dend 	= 30		*spinescale 

git_dend 	= 0		*spinescale
gca_dend 	= 0.5		*spinescale
gka_dend 	= 0.02	*spinescale 

git_basal 	= 0.0003	*spinescale
gca_basal 	= 0.7		*spinescale
gka_basal 	= 0.02	*spinescale 
		
gca_soma 	= 0.5 
git_soma 	= 0

vshift_na 	= -13

// the reconstructed axon 
	axon {insert na gbar_na = gna_node
		insert kv gbar_kv = gkv_axon}

	soma {insert na gbar_na = gna_node
 		insert kv gbar_kv = gkv_axon}

	for i=0,13 {
		dend1[i]  {insert na gbar_na=gna_node
			insert kv gbar_kv = gkv_axon}}

// all dendrites 
	for i=28,1090 {
		dend1[i] {
		insert na 		gbar_na = gna_dend
		insert kv 		gbar_kv = gkv_dend
		insert ka 		gbar_ka = gka_dend
  		}
	}
// specific soma 
	for i=14,27 {
		dend1[i] {
		insert na 		gbar_na = gna_soma
		insert kv 		gbar_kv = gkv_soma
		} 
  	}
	forall {ena = 60
	 ek = -90}
}

// ---------------------------------------------------------------------
// Calcium enhancement to reproduce frequency effect (Larkum et al,1999)
// ----------------------------------------------------------------------

proc addca() {
	// all dendrites 
	for i=28,1090 {
		dend1[i] {
		insert cad 
		insert ca 		gbar_ca = gca_dend
		insert it 		gbar_it = git_dend
  		}
	}
	// specific soma 
	for i=14,27 {
		dend1[i] {
		insert ca 		gbar_ca = gca_soma
		insert cad
		insert it		gbar_it = git_soma
		}
	}
	forall if(ismembrane("ca_ion")) {
    		eca = 140
    		ion_style("ca_ion",0,1,0,0,0)
    		vshift_ca = 10
	} 
}

proc boostca() {

	forall { 	vh1_it    = 56
			vh2_it    = 415
			ah_it     = 30				
			v12m_it   = 45
			v12h_it   = 65  
			am_it     = 3
			vshift_it = 10
			vm1_it    = 50
			vm2_it    = 125
		}

}

proc init_basals() {
	forsec basal_dendrites {
		gbar_ca = gca_basal 
		gbar_it = git_basal 
		gbar_ka = gka_basal
		}
}

Loading data, please wait...