High frequency oscillations in a hippocampal computational model (Stacey et al. 2009)

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Accession:135902
"... Using a physiological computer model of hippocampus, we investigate random synaptic activity (noise) as a potential initiator of HFOs (high-frequency oscillations). We explore parameters necessary to produce these oscillations and quantify the response using the tools of stochastic resonance (SR) and coherence resonance (CR). ... Our results show that, under normal coupling conditions, synaptic noise was able to produce gamma (30–100 Hz) frequency oscillations. Synaptic noise generated HFOs in the ripple range (100–200 Hz) when the network had parameters similar to pathological findings in epilepsy: increased gap junctions or recurrent synaptic connections, loss of inhibitory interneurons such as basket cells, and increased synaptic noise. ... We propose that increased synaptic noise and physiological coupling mechanisms are sufficient to generate gamma oscillations and that pathologic changes in noise and coupling similar to those in epilepsy can produce abnormal ripples."
Reference:
1 . Stacey WC, Lazarewicz MT, Litt B (2009) Synaptic noise and physiological coupling generate high-frequency oscillations in a hippocampal computational model. J Neurophysiol 102:2342-57 [PubMed]
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Model Information (Click on a link to find other models with that property)
Model Type: Realistic Network;
Brain Region(s)/Organism: Hippocampus;
Cell Type(s): Hippocampus CA1 pyramidal GLU cell; Hippocampus CA3 pyramidal GLU cell; Hippocampus CA1 interneuron oriens alveus GABA cell; Hippocampus CA1 basket cell;
Channel(s): I Na,t; I A; I K; I h;
Gap Junctions: Gap junctions;
Receptor(s): GabaA; AMPA; NMDA;
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Oscillations;
Implementer(s): Lazarewicz, Maciej [mlazarew at gmu.edu]; Stacey, William [wstacey at med.umich.edu];
Search NeuronDB for information about:  Hippocampus CA1 pyramidal GLU cell; Hippocampus CA3 pyramidal GLU cell; Hippocampus CA1 interneuron oriens alveus GABA cell; GabaA; AMPA; NMDA; I Na,t; I A; I K; I h;
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
//
//  NOTICE OF COPYRIGHT AND OWNERSHIP OF SOFTWARE
//
// Copyright 2010, The University Of Michigan
// 	
//   All rights reserved.
//   For research use only; commercial use prohibited.
//   No Distribution without permission of William Stacey
//   wstacey@umich.edu
//
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%



begintemplate SynObj

public addSyn, printSyn, printLoc, connect2syn, printCon, getSyn, addNetCon, addSynStim, removeConnections, conList, synList

objref  synList, conList, loc, stimList, this
 
strdef cmd
 
 
// =================================================================================================
//
// init()
//
// =================================================================================================
proc init() {
    synList  = new List()
    conList  = new List()
    stimList = new List()

    loc = new SectionRef()
}




// =================================================================================================
//
// connect2syn
//
// =================================================================================================
proc connect2syn() {

    if (numarg()==5) {
        
        conList.prepend( new NetCon($o1,  synList.object($2), $3, $4, $5 ) )
    
    } else {
        
        print "USAGE: connect2syn(src obj, syn nr, threshold, delay, weight)"
        
    }
}




// =================================================================================================
//
// removeConnections
//
// =================================================================================================
proc removeConnections() {

	conList.remove_all()
}




// =================================================================================================
//
// addNetCon(nc, threshold, delay, weight) - for MPI
//
// =================================================================================================
proc addNetCon() {

    if (numarg()==1 || numarg()==4 ) {
    
        conList.prepend($o1)
    
        if (numarg()==4) {
  
                $o1.threshold = $2
                $o1.delay     = $3
                $o1.weight    = $4
        
        }
        
    } else {
        
        print "USAGE: connect(nc, [threshold, delay, weight])"
        
    }
}




// =================================================================================================
//
// addSyn( tau1 (ms), tau2 (ms), Erev (mV), mode, synLoc )
//
// mode: 2 - NMDA
// =================================================================================================
func addSyn() {

    last = synList.count()
    
    if (numarg()==5) {
        show_errmess_always(1)
        sprint(cmd, "loc.sec synList.append(new %s(%g))", $s4, $5)
        execute1(cmd, this)
    	//if ($4==0) loc.sec synList.append(new Exp2Syn($5))
        //if ($4==1) loc.sec synList.append(new Exp2SynAMPA($5))
        //if ($4==2) loc.sec synList.append(new Exp2SynNMDA($5))
        //if ($4==3) loc.sec synList.append(new Exp2SynNMDAperm($5))
            
        synList.o(last).tau1 = $1
        synList.o(last).tau2 = $2
        synList.o(last).e    = $3
        //loc.sec printf("%s %s(%g) %g %g %g\n", secname(), $s4, $5, synList.o(last).tau1, synList.o(last).tau2, synList.o(last).e)
        return (last)

    } else {
        
        print "USAGE: addSyn(tau1 (ms), tau2 (ms), eRev (mV), modFileName, synLoc)"
        return -1
    }
}




// =================================================================================================
//
// addSynStim
//
// =================================================================================================
func addSynStim() {
        
    if (numarg()==9 || numarg()==10) {

            tau1  = $1
            tau2  = $2
            eRev  = $3
            f     = $4
            nr_sp = $5
            start = $6
            noise = $7
            g     = $8
            gid   = $9

            if (numarg()==9){
    
                stim_syn_nr = addSyn(tau1, tau2, eRev)
            
            }else{
                
                syn_mode = $10
                stim_syn_nr = addSyn(tau1, tau2, eRev, syn_mode)

            }

            loc.sec stimList.append(new NetStim())
            last  = stimList.count()
            
            if (f>0) {

                stimList.o(last-1).interval = 1000/f
                stimList.o(last-1).number   = nr_sp

            }else{

                stimList.o(last-1).interval = 1
                stimList.o(last-1).number   = 0

            }

            stimList.o(last-1).start    = start
            stimList.o(last-1).noise    = noise
            stimList.o(last-1).seed((startsw()*gid)%10000)

            connect2syn(stimList.o(last-1), stim_syn_nr, 0, 0, g)
        
            return stim_syn_nr

    } else {
        
        print "USAGE: addSynStim(tau1 (ms), tau2 (ms), eRev (mV), f (Hz), number spikes, start time (ms), noise <0-1>, g (nS), gid )"
        return -1
    }

}




// =================================================================================================
//
// printLoc
//
// =================================================================================================
proc printLoc() {
    
    loc.sec print secname() 
}




// =================================================================================================
//
// getSyn(nr) - return reference to the synapse #nr
//
// =================================================================================================
obfunc getSyn() {
    
    return synList.object($1)
}




// =================================================================================================
//
// printSyn
//
// =================================================================================================
proc printSyn() {
    for i=0, synList.count()-1 {
        loc.sec printf("%d, %s, tau1= %g ms, tau2= %g ms, e= %g mV loc= %s\n", i, synList.object(i), synList.object(i).tau1, synList.object(i).tau2, synList.object(i).e, secname() )
    }
}




strdef xs, ys
objref c, c1

// =================================================================================================
//
// printCon
//
// =================================================================================================
proc printCon() {

    
    for i=0, conList.count()-1 {
        c  = conList.object(i)
        x  = c.preloc
        xs = secname()
        pop_section()
        y  = c.postloc()
        ys = secname()
        pop_section()
        c1 = c.syn()
        
        loc.sec printf("%d, %s(%g) -> %s(%g) %s, tau1= %g (ms), tau2= %g (ms), eRev= %g (mV), loc= %s\n", i, xs, x, ys, y, c1, c1.tau1, c1.tau2, c1.e,  secname() )
        
    }
}




endtemplate SynObj