Single compartment: nonlinear a5-GABAAR controls synaptic NMDAR activation (Schulz et al 2018)

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Accession:258946
This study shows that IPSCs mediated by a5-subunit containing GABAA receptors are strongly outward-rectifying generating 4-fold larger conductances above -50?mV than at rest. This model shows that synaptic activation of these receptors can very effectively control voltage-dependent NMDA-receptor activation. The files contain the NEURON code for Fig.6 and Fig.7. The model is a single dendritic compartment with one glutamatergic and GABAergic synapse. Physiological properties of GABA synapses were modeled as determined by optogenetic activation of inputs during voltage-clamp recordings in Schulz et al. 2018.
Reference:
1 . Schulz JM, Knoflach F, Hernandez MC, Bischofberger J (2018) Dendrite-targeting interneurons control synaptic NMDA-receptor activation via nonlinear a5-GABAA receptors. Nat Commun 9:3576 [PubMed]
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Model Information (Click on a link to find other models with that property)
Model Type:
Brain Region(s)/Organism:
Cell Type(s):
Channel(s):
Gap Junctions:
Receptor(s): AMPA; GabaA; NMDA;
Gene(s):
Transmitter(s): Gaba; Glutamate;
Simulation Environment: NEURON;
Model Concept(s):
Implementer(s): Schulz, Jan M [j.schulz at unibas.ch];
Search NeuronDB for information about:  GabaA; AMPA; NMDA; Gaba; Glutamate;
n_glu_syn=3
n_GABA_syn=2
// synaptic inputs
objref nsGABA[n_GABA_syn],ncGABA[n_GABA_syn],synGABA[n_GABA_syn]
objref nsAMPA[n_glu_syn],ncAMPA[n_glu_syn],synAMPA[n_glu_syn]
objref nsNMDA[n_glu_syn],ncNMDA[n_glu_syn],synNMDA[n_glu_syn]

// parameters
celsius = 35
v_init=-70
global_ra=200.00 	// internal resistivity in ohm-cm 
Cm= 1               // specific membrane capacitance in uF/cm^2 
Rm=10000		// specific membrane resistivity in ohm-cm^2 
Vleak=-70 
Vrest=-70	

nmdaTau1 = 3 // faster dynamics measured at hyperpolarised membrane potential
nmdaTau2 = 35 // see also Kampa at al. J Physiol 2004

// Inhibition parameters.
inhRev = -70 

// make dendritic compartment
create dend

dend {
	nseg =51 
	diam = 2
	L = 100
    insert pas	
    e_pas=Vleak  
    g_pas=1/Rm   
    Ra=global_ra  
    cm=Cm
    }

// insert a Glu and a GABA synapse
x=0.5
for (ii=0; ii<n_glu_syn; ii=ii+1){
    dend synAMPA[ii] = new excSyn(x)
    synAMPA[ii].isOn=1
    nsAMPA[ii] = new NetStim()
    ncAMPA[ii] = new NetCon(nsAMPA[ii], synAMPA[ii])

    dend synNMDA[ii] = new Exp2SynNmda(x)
    synNMDA[ii].isOn=1
    nsNMDA[ii] = new NetStim()
    ncNMDA[ii] = new NetCon(nsNMDA[ii], synNMDA[ii])
}

x=0.5
for (ii=0; ii<n_GABA_syn; ii=ii+1){
    dend synGABA[ii] = new inhSyn(x)
    synGABA[ii].isOn=1
    nsGABA[ii] = new NetStim()
    ncGABA[ii] = new NetCon(nsGABA[ii], synGABA[ii])
    }