/*----------------------------------------------------------------------------
Detailed kinetic synapse mechanism
----------------------------------
Demo file to show the behavior of a synaptic currents mediated by
glutamate NMDA receptors, using a detailed kinetic model of these
receptors and a kinetic model for the release of transmitter.
Kinetic model from Clements & Westbrook, Neuron 7: 605, 1991.
See details in:
Destexhe, A., Mainen, Z.F. and Sejnowski, T.J. Kinetic models of
synaptic transmission. In: Methods in Neuronal Modeling (2nd edition;
edited by Koch, C. and Segev, I.), MIT press, Cambridge, 1996.
Written by Alain Destexhe, Laval University, 1995
----------------------------------------------------------------------------*/
//----------------------------------------------------------------------------
// load and define general graphical procedures
//----------------------------------------------------------------------------
xopen("$(NEURONHOME)/lib/hoc/stdrun.hoc")
objectvar g[20] // max 20 graphs
ngraph = 0
proc addgraph() { local ii // define subroutine to add a new graph
// addgraph("variable", minvalue, maxvalue)
ngraph = ngraph+1
ii = ngraph-1
g[ii] = new Graph()
g[ii].size(0,tstop,$2,$3)
g[ii].xaxis()
g[ii].yaxis()
g[ii].addvar($s1,1,0)
g[ii].save_name("graphList[0].")
graphList[0].append(g[ii])
}
if(ismenu==0) {
nrnmainmenu() // create main menu
nrncontrolmenu() // crate control menu
ismenu=1
}
//----------------------------------------------------------------------------
// general parameters
//----------------------------------------------------------------------------
dt=0.025
tstop = 2500
runStopAt = tstop
steps_per_ms = 1/dt
celsius = 36
v_init = -70
//----------------------------------------------------------------------------
// create compartments and insert passive properties
//----------------------------------------------------------------------------
create PRE,POST
forall {
diam=10
L=10
insert pas
g_pas=1/5000
e_pas=v_init
}
//----------------------------------------------------------------------------
// insert presynaptic mechanisms
//----------------------------------------------------------------------------
access PRE // insert Hodgk-Hux. Na+ and K+ currents for spikes
insert relramp // transmitter release
//----------------------------------------------------------------------------
// insert postsynaptic mechansisms
//----------------------------------------------------------------------------
objectvar c
c = new NMDA5() // create synapse
POST c.loc(0.5) // assign postsynaptic compartment
setpointer c.C, PRE.T_relramp(0.5) // assign presynaptic compartment
Erev_NMDA5 = 0 // (mV) reversal potential (E_K)
mg_NMDA5 = 0 // put in zero magnesium for the demo
// parameters from Hessler Shirke & Malinow 1993
Rb_NMDA5 = 5e-3 // (/uM /ms) : binding
Ru_NMDA5 = 0.0045 // (/ms) : unbinding
Rd_NMDA5 = 0.01 // (/ms) : desensitization
Rr_NMDA5 = 0.016 // (/ms) : resensitization
Ro_NMDA5 = 0.08 // (/ms) : opening
Rc_NMDA5 = 0.12 // (/ms) : closing
c.gmax = 50 // (pS) maximum conductance
//----------------------------------------------------------------------------
// add graphs
//----------------------------------------------------------------------------
addgraph("PRE.T_relramp(0.5)",0,1.5)
addgraph("c.inmda",-0.001, 0.0001)