Ribbon Synapse (Sikora et al 2005)

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Accession:50997
A model of the ribbon synapse was developed to replicate both pre- and postsynaptic functions of this glutamatergic juncture. The presynaptic portion of the model is rich in anatomical and physiological detail and includes multiple release sites for each ribbon based on anatomical studies of presynaptic terminals, presynaptic voltage at the terminal, the activation of voltage-gated calcium channels and a calcium-dependent release mechanism whose rate varies as a function of the calcium concentration that is monitored at two different sites which control both an ultrafast, docked pool of vesicles and a release ready pool of tethered vesicles. See paper for more and details.
Reference:
1 . Sikora MA, Gottesman J, Miller RF (2005) A computational model of the ribbon synapse. J Neurosci Methods 145:47-61 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Synapse;
Brain Region(s)/Organism:
Cell Type(s): Retina ganglion GLU cell; Retina bipolar GLU cell;
Channel(s): I L high threshold;
Gap Junctions:
Receptor(s): AMPA; NMDA;
Gene(s):
Transmitter(s): Glutamate;
Simulation Environment: NEURON;
Model Concept(s): Intrinsic plasticity; Calcium dynamics;
Implementer(s): Sikora, Michael [Sikora at umn.edu];
Search NeuronDB for information about:  Retina ganglion GLU cell; Retina bipolar GLU cell; AMPA; NMDA; I L high threshold; Glutamate;
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()}
{pwman_place(0,0,0)}
{
xpanel("RunControl", 0)
v_init = -65
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 = 37.41
xvalue("t","t", 2 )
tstop = 50
xvalue("Tstop","tstop", 1,"tstop_changed()", 0, 1 )
dt = 0.01
xvalue("dt","dt", 1,"setdt()", 0, 1 )
steps_per_ms = 100
xvalue("Points plotted/ms","steps_per_ms", 1,"setdt()", 0, 1 )
xcheckbox("Quiet",&stdrun_quiet,"")
realtime = 7
xvalue("Real Time","realtime", 0,"", 0, 1 )
xpanel(417,602)
}
{
save_window_ = new Graph(0)
save_window_.size(0,51,0,10000)
scene_vector_[2] = save_window_
{save_window_.view(0, 0, 751, 10000, 388, 53, 640, 343.2)}
save_window_.family("total_count_ribbon_ca")
graphList[2].append(save_window_)
save_window_.save_name("graphList[2].")
save_window_.addvar("total_count_ribbon_ca", 1, 1, 0.8, 0.9, 2)
save_window_.exec_menu("Keep Lines")
}
{
xpanel("caconc[0] at bp(0.5)", 0)
xlabel("caconc[0] at bp(0.5)")
calcium.Alpha_Max = 0
xvalue("Alpha_Max","calcium.Alpha_Max", 1,"", 0, 1 )
calcium.Alpha_Delay = 0
xvalue("Alpha_Delay","calcium.Alpha_Delay", 1,"", 0, 1 )
calcium.Alpha_tau = 0.1
xvalue("Alpha_tau","calcium.Alpha_tau", 1,"", 0, 1 )
calcium.DC_Level = 0.2
xvalue("DC_Level","calcium.DC_Level", 1,"", 0, 1 )
calcium.DC_Delay = 0
xvalue("DC_Delay","calcium.DC_Delay", 1,"", 0, 1 )
calcium.DC_Off = 2000
xvalue("DC_Off","calcium.DC_Off", 1,"", 0, 1 )
calcium.Ramp_Max = 0
xvalue("Ramp_Max","calcium.Ramp_Max", 1,"", 0, 1 )
calcium.Ramp_Delay = 0
xvalue("Ramp_Delay","calcium.Ramp_Delay", 1,"", 0, 1 )
calcium.Ramp_Off = 0
xvalue("Ramp_Off","calcium.Ramp_Off", 1,"", 0, 1 )
calcium.Slope_UP = 0
xvalue("Slope_UP","calcium.Slope_UP", 1,"", 0, 1 )
calcium.Slope_DOWN = 0
xvalue("Slope_DOWN","calcium.Slope_DOWN", 1,"", 0, 1 )
calcium.alpend = 0
xvalue("alpend","calcium.alpend", 1,"", 0, 1 )
xpanel(21,572)
}
{
save_window_ = new Graph(0)
save_window_.size(0,50,0,1)
scene_vector_[3] = save_window_
{save_window_.view(25, 0, 50, 0.7, 11, 167, 346.56, 199.36)}
graphList[2].append(save_window_)
save_window_.save_name("graphList[2].")
save_window_.label(0.127557, 0.814627, "Fig.7 in the paper is replicated here.", 2, 1, 0, 0, 1)
save_window_.label(0.127796, 0.709311, "Pre-synaptic calcium concentration (in mM) is", 2, 1, 0, 0, 1)
save_window_.label(0.126264, 0.604203, "set using DC_Level in caconc[0]", 2, 1, 0, 0, 1)
save_window_.xaxis(3)
save_window_.yaxis(3)
}
objectvar scene_vector_[1]
{doNotify()}

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