Competition for AP initiation sites in a circuit controlling simple learning (Cruz et al. 2007)

 Download zip file   Auto-launch 
Help downloading and running models
Accession:117459
"The spatial and temporal patterns of action potential initiations were studied in a behaving leech preparation to determine the basis of increased firing that accompanies sensitization, a form of non-associative learning requiring the S-interneurons. ... The S-interneurons, one in each ganglion and linked by electrical synapses with both neighbors to form a chain, are interposed between sensory and motor neurons. ... the single site with the largest initiation rate, the S-cell in the stimulated segment, suppressed initiations in adjacent ganglia. Experiments showed this was both because (1) it received the earliest, greatest input and (2) the delayed synaptic input to the adjacent S-cells coincided with the action potential refractory period. A compartmental model of the S-cell and its inputs showed that a simple, intrinsic mechanism of inexcitability after each action potential may account for suppression of impulse initiations. Thus, a non-synaptic competition between neurons alters synaptic integration in the chain. In one mode, inputs to different sites sum independently, whereas in another, synaptic input to a single site precisely specifies the overall pattern of activity."
Reference:
1 . Cruz GE, Sahley CL, Muller KJ (2007) Neuronal competition for action potential initiation sites in a circuit controlling simple learning. Neuroscience 148:65-81 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Realistic Network; Neuron or other electrically excitable cell;
Brain Region(s)/Organism: Leech;
Cell Type(s): Leech S cell;
Channel(s): I Na,t; I K,leak;
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s): Serotonin;
Simulation Environment: NEURON;
Model Concept(s): Action Potential Initiation; Activity Patterns; Spatio-temporal Activity Patterns;
Implementer(s): Cruz, Ginny [gcruz at monell.org];
Search NeuronDB for information about:  I Na,t; I K,leak; Serotonin;
{load_file("nrngui.hoc")}
objectvar save_window_, rvp_
objectvar scene_vector_[4]
objectvar ocbox_, ocbox_list_, scene_, scene_list_
{ocbox_list_ = new List()  scene_list_ = new List()}

//Begin PointProcessGroupManager
{
load_file("pointgrp.hoc")
}
{
ocbox_ = new PointProcessGroupManager(0)
}
{object_push(ocbox_)}
{
ms = new MechanismStandard("IClamp")
ms.set("del", 0, 0)
ms.set("dur", 0, 0)
ms.set("amp", 0, 0)
mnews("IClamp", ms)
select(0)
execute("Ssoma[1] ocbox_.move(0.5)")
ms = new MechanismStandard("AlphaSynapse")
ms.set("onset", 0, 0)
ms.set("tau", 0.1, 0)
ms.set("gmax", 0, 0)
ms.set("e", 0, 0)
mnews("AlphaSynapse", ms)
select(1)
execute("Sax[1] ocbox_.move(0.52525)")
ms = new MechanismStandard("AlphaSynapse")
ms.set("onset", 0, 0)
ms.set("tau", 0.1, 0)
ms.set("gmax", 0.27, 0)
ms.set("e", 0, 0)
mnews("AlphaSynapse", ms)
select(2)
execute("Sax[2] ocbox_.move(0.51275)")
}
{object_pop() doNotify()}
{
ocbox_ = ocbox_.v1
ocbox_.map("PointProcessGroupManager", 306, 337, 552.6, 412.2)
}
objref ocbox_
//End PointProcessGroupManager

{
save_window_ = new Graph(0)
save_window_.size(0,30,-80,40)
scene_vector_[3] = save_window_
{save_window_.view(0, -80, 30, 120, 382, 1, 837.9, 200.8)}
graphList[0].append(save_window_)
save_window_.save_name("graphList[0].")
save_window_.addvar("Ssoma[1].v( 0.5 )", 1, 1, 0.840816, 1.00757, 2)
}
{
xpanel("RunControl", 0)
v_init = -63
xvalue("Init","v_init", 1,"stdinit()", 1, 1 )
xbutton("Init & Run","run()")
xbutton("Stop","stoprun=1")
runStopAt = 5
xvalue("Continue til","runStopAt", 1,"{continuerun(runStopAt) stoprun=1}", 1, 1 )
runStopIn = 1
xvalue("Continue for","runStopIn", 1,"{continuerun(t + runStopIn) stoprun=1}", 1, 1 )
xbutton("Single Step","steprun()")
t = 30
xvalue("t","t", 2 )
tstop = 30
xvalue("Tstop","tstop", 1,"tstop_changed()", 0, 1 )
dt = 0.025
xvalue("dt","dt", 1,"setdt()", 0, 1 )
steps_per_ms = 40
xvalue("Points plotted/ms","steps_per_ms", 1,"setdt()", 0, 1 )
screen_update_invl = 0.05
xvalue("Scrn update invl","screen_update_invl", 1,"", 0, 1 )
realtime = 30.67
xvalue("Real Time","realtime", 0,"", 0, 1 )
xpanel(12,102)
}
{
xpanel("Sax[1](0 - 1) (Parameters)", 0)
xlabel("Sax[1](0 - 1) (Parameters)")
Sax[1].nseg = 3000
xvalue("nseg","Sax[1].nseg", 1,"", 0, 0 )
Sax[1].L = 6000
xvalue("L","Sax[1].L", 1,"define_shape()", 0, 0 )
Sax[1].cm = 1
xvalue("cm","Sax[1].cm", 1,"", 0, 0 )
Sax[1].diam = 7
xvalue("diam","Sax[1].diam", 1,"", 0, 0 )
Sax[1].gnabar_hh2 = 0.12
xvalue("gnabar_hh2","Sax[1].gnabar_hh2", 1,"", 0, 0 )
Sax[1].gkbar_hh2 = 0.036
xvalue("gkbar_hh2","Sax[1].gkbar_hh2", 1,"", 0, 0 )
Sax[1].gl_hh2 = 0.0003
xvalue("gl_hh2","Sax[1].gl_hh2", 1,"", 0, 0 )
Sax[1].el_hh2 = -54.3
xvalue("el_hh2","Sax[1].el_hh2", 1,"", 0, 0 )
Sax[1].mvhalfa_hh2 = -45
xvalue("mvhalfa_hh2","Sax[1].mvhalfa_hh2", 1,"", 0, 0 )
Sax[1].mvhalfb_hh2 = -55
xvalue("mvhalfb_hh2","Sax[1].mvhalfb_hh2", 1,"", 0, 0 )
Sax[1].hvhalfa_hh2 = -62
xvalue("hvhalfa_hh2","Sax[1].hvhalfa_hh2", 1,"", 0, 0 )
Sax[1].hvhalfb_hh2 = -31
xvalue("hvhalfb_hh2","Sax[1].hvhalfb_hh2", 1,"", 0, 0 )
Sax[1].nvhalfa_hh2 = -53
xvalue("nvhalfa_hh2","Sax[1].nvhalfa_hh2", 1,"", 0, 0 )
Sax[1].nvhalfb_hh2 = -63
xvalue("nvhalfb_hh2","Sax[1].nvhalfb_hh2", 1,"", 0, 0 )
Sax[1].ena = 50
xvalue("ena","Sax[1].ena", 1,"", 0, 0 )
Sax[1].ek = -68
xvalue("ek","Sax[1].ek", 1,"", 0, 0 )
xpanel(878,590)
}
{
xpanel("Sax[2](0 - 1) (Parameters)", 0)
xlabel("Sax[2](0 - 1) (Parameters)")
Sax[2].nseg = 3000
xvalue("nseg","Sax[2].nseg", 1,"", 0, 0 )
Sax[2].L = 6000
xvalue("L","Sax[2].L", 1,"define_shape()", 0, 0 )
Sax[2].cm = 1
xvalue("cm","Sax[2].cm", 1,"", 0, 0 )
Sax[2].diam = 7
xvalue("diam","Sax[2].diam", 1,"", 0, 0 )
Sax[2].gnabar_hh2 = 0.12
xvalue("gnabar_hh2","Sax[2].gnabar_hh2", 1,"", 0, 0 )
Sax[2].gkbar_hh2 = 0.036
xvalue("gkbar_hh2","Sax[2].gkbar_hh2", 1,"", 0, 0 )
Sax[2].gl_hh2 = 0.0003
xvalue("gl_hh2","Sax[2].gl_hh2", 1,"", 0, 0 )
Sax[2].el_hh2 = -54.3
xvalue("el_hh2","Sax[2].el_hh2", 1,"", 0, 0 )
Sax[2].mvhalfa_hh2 = -45
xvalue("mvhalfa_hh2","Sax[2].mvhalfa_hh2", 1,"", 0, 0 )
Sax[2].mvhalfb_hh2 = -55
xvalue("mvhalfb_hh2","Sax[2].mvhalfb_hh2", 1,"", 0, 0 )
Sax[2].hvhalfa_hh2 = -62
xvalue("hvhalfa_hh2","Sax[2].hvhalfa_hh2", 1,"", 0, 0 )
Sax[2].hvhalfb_hh2 = -31
xvalue("hvhalfb_hh2","Sax[2].hvhalfb_hh2", 1,"", 0, 0 )
Sax[2].nvhalfa_hh2 = -53
xvalue("nvhalfa_hh2","Sax[2].nvhalfa_hh2", 1,"", 0, 0 )
Sax[2].nvhalfb_hh2 = -63
xvalue("nvhalfb_hh2","Sax[2].nvhalfb_hh2", 1,"", 0, 0 )
Sax[2].ena = 50
xvalue("ena","Sax[2].ena", 1,"", 0, 0 )
Sax[2].ek = -68
xvalue("ek","Sax[2].ek", 1,"", 0, 0 )
xpanel(1202,588)
}
{
xpanel("Temperature", 0)
celsius = 12
xvalue("celsius","celsius", 1,"", 0, 1 )
xpanel(18,546)
}
{
xpanel("forall Ra=global_ra", 0)
global_ra = 100
xvalue("global Ra","global_ra", 1,"set_ra()", 1, 1 )
xpanel(12,666)
}
objectvar scene_vector_[1]
{doNotify()}

Loading data, please wait...