CA1 pyramidal neuron: dendritic Ca2+ inhibition (Muellner et al. 2015)

 Download zip file 
Help downloading and running models
In our experimental study, we combined paired patch-clamp recordings and two-photon Ca2+ imaging to quantify inhibition exerted by individual GABAergic contacts on hippocampal pyramidal cell dendrites. We observed that Ca2+ transients from back-propagating action potentials were significantly reduced during simultaneous activation of individual nearby GABAergic synapses. To simulate dendritic Ca2+ inhibition by individual GABAergic synapses, we employed a multi-compartmental CA1 pyramidal cell model with detailed morphology, voltage-gated channel distributions, and calcium dynamics, based with modifications on the model of Poirazi et al., 2003, modelDB accession # 20212.
1 . Müllner FE, Wierenga CJ, Bonhoeffer T (2015) Precision of Inhibition: Dendritic Inhibition by Individual GABAergic Synapses on Hippocampal Pyramidal Cells Is Confined in Space and Time. Neuron 87:576-89 [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: Hippocampus;
Cell Type(s): Hippocampus CA1 pyramidal GLU cell;
Channel(s): I Calcium; I Sodium; I Potassium; I h;
Gap Junctions:
Transmitter(s): Gaba;
Simulation Environment: NEURON;
Model Concept(s): Action Potentials; Dendritic Action Potentials; Active Dendrites; Calcium dynamics;
Implementer(s): Muellner, Fiona E [fiona.muellner at];
Search NeuronDB for information about:  Hippocampus CA1 pyramidal GLU cell; I h; I Sodium; I Calcium; I Potassium; Gaba;

strdef accstr    // not confuse experimental variable bindings with neurophysiological variable bindings
objref econ                          // Create an experiment object
econ=new ExperimentControl(show_errs,debug_lev)
econ.self_define(econ) 		// points the object at itself
econ.morphology_dir = "../morphology/n123"                             // Setup morphology directory
econ.generic_dir = "../experiment/"                                    // Setup directory with cell-setup file
econ.add_lib_dir("Terrence","../lib")                                  // Setup directory with library functions 

if (unix_mac_pc() ==1 ) {
	econ.data_dir       = "data"                       // Define directory to save produced data 
	sprint(econ.syscmd, "mkdir -p %s", econ.data_dir)  // make the data directory

// *******************************************************
// Setup cell
// *******************************************************

objref dendrv
dendrv = new Vector(0)

// Define spine position
dendr = 3
spinepos = 0.1

// Define spine geometry
neckW = 0.147
neckL = 0.667
headW = 0.519
headL = 0.519

econ.xopen_geometry_dependent("cell_+spine")    // load the raw cell morphology
econ.xopen_geometry_dependent("cell-analysis")     // load user-defined semantics on morphology 

printf("Opening cell setup\n")
econ.xopen_generic("cell-setup_regular")                   // load the cell-setup file (define specific 
printf("Opened. Setting up cell\n")                // channels, membrane properties etc)

// *******************************************************
// Set simulation parameters
// *******************************************************

econ.defvar("Simulation Control", "tstop", "30", "Defines when the simulation stops.")
econ.defvar("Simulation Control", "dt", "0.025", "Timestep") // 0.1 originally
econ.defvar("Simulation Control", "steps_per_ms", "40", "How many points are plotted per ms")

// *******************************************************
// Set maximum segment length 5um and nseg = odd multiple of 5
// *******************************************************

for i=0,118 {
apical_dendrite[i] {nseg=int((int(L/5)+5)/10)*10+5}

// *******************************************************
// Initialize experiment
// *******************************************************

access soma

v_init = -70

forall {insert cldifus}
forall {Ra = 100}


Loading data, please wait...