Computational analysis of NN activity and spatial reach of sharp wave-ripples (Canakci et al 2017)

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Accession:230861
Network oscillations of different frequencies, durations and amplitudes are hypothesized to coordinate information processing and transfer across brain areas. Among these oscillations, hippocampal sharp wave-ripple complexes (SPW-Rs) are one of the most prominent. SPW-Rs occurring in the hippocampus are suggested to play essential roles in memory consolidation as well as information transfer to the neocortex. To-date, most of the knowledge about SPW-Rs comes from experimental studies averaging responses from neuronal populations monitored by conventional microelectrodes. In this work, we investigate spatiotemporal characteristics of SPW-Rs and how microelectrode size and distance influence SPW-R recordings using a biophysical model of hippocampus. We also explore contributions from neuronal spikes and synaptic potentials to SPW-Rs based on two different types of network activity. Our study suggests that neuronal spikes from pyramidal cells contribute significantly to ripples while high amplitude sharp waves mainly arise from synaptic activity. Our simulations on spatial reach of SPW-Rs show that the amplitudes of sharp waves and ripples exhibit a steep decrease with distance from the network and this effect is more prominent for smaller area electrodes. Furthermore, the amplitude of the signal decreases strongly with increasing electrode surface area as a result of averaging. The relative decrease is more pronounced when the recording electrode is closer to the source of the activity. Through simulations of field potentials across a high-density microelectrode array, we demonstrate the importance of finding the ideal spatial resolution for capturing SPW-Rs with great sensitivity. Our work provides insights on contributions from spikes and synaptic potentials to SPW-Rs and describes the effect of measurement configuration on LFPs to guide experimental studies towards improved SPW-R recordings.
Reference:
1 . Canakci S, Toy MF, Inci AF, Liu X, Kuzum D (2017) Computational analysis of network activity and spatial reach of sharp wave-ripples. PLoS One 12:e0184542 [PubMed]
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 CA1 basket cell;
Channel(s): I Na,t; I A; I K; I h;
Gap Junctions: Gap junctions;
Receptor(s): NMDA; GabaA; Glutamate;
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Oscillations; Spatio-temporal Activity Patterns;
Implementer(s): Canakci, Sadullah [scanakci at bu.edu]; Inci, Ahmet F [afinci at sabanciuniv,edu]; Toy, Faruk [faruk.toy at metu.edu.tr]; Liu, Xin [xil432 at end.ucsd.edu]; Kuzum, Duygu [dkuzum at eng.ucsd.edu];
Search NeuronDB for information about:  Hippocampus CA1 pyramidal GLU cell; GabaA; NMDA; Glutamate; I Na,t; I A; I K; I h;
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
//
// NOTICE OF COPYRIGHT AND OWNERSHIP OF SOFTWARE
//
// Copyright 2007, The University Of Pennsylvania
// 	School of Engineering & Applied Science.
//   All rights reserved.
//   For research use only; commercial use prohibited.
//   Distribution without permission of Maciej T. Lazarewicz not permitted.
//   mlazarew@seas.upenn.edu
//
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%



begintemplate IApp

public set, get, getloc, set_random, getConv, setValue, set_random_play

objref  iapp, iappR, loc, rR, rC, rD




// =================================================================================================
//
// init()
//
// ================================================================================================= 
proc init() {

    loc = new SectionRef()
	loc.sec iappR = new IClamp(0.5)
    loc.sec iapp  = new IClamp(0.5)
}




// =================================================================================================
//
// set()
//
// ================================================================================================= 
proc set() {
    //print "SET"
    if (numarg()==1 || numarg()==2) {
    
        iapp.dur = 1e9        
        iapp.del = 0

        if (numarg()==2) iapp.del = $2

        loc.sec iapp.amp = $1 * area(0.5) * 1e-5
    
    } else {
        
        print "USAGE: set( i (uA/cm2) )"
        
    }
}




// =================================================================================================
//
// getConv()
//
// ================================================================================================= 
func getConv() { local c

    loc.sec  c = area(0.5) * 1e-5 
    return c
}




// ========================================================================
//
// setValue( i [nA], { del [ms]} )
//
// ========================================================================
proc setValue() {
    //print "SETVALUE"
    if (numarg()==1 || numarg()==2) {
    
        iapp.dur = 1e9        
        iapp.del = 0

        if (numarg()==2) iapp.del = $2

        loc.sec iapp.amp = $1
    
    } else {
        
        print "USAGE: set( i (nA) )"
        
    }
}



// =================================================================================================
//
// set_random_play(mean, sd, isUnitsPerCm2, gid)
//
// ================================================================================================= 
proc set_random_play() {local mean, sd
   
   		mean          = $1
   		sd            = $2
   		isUnitsPerCm2 = $3
   		
   		//loc.sec print secname(), " mean=", mean, " sd=", sd, "UNITS:", isUnitsPerCm2
   		
   		if (isUnitsPerCm2) {
   		// conversion from uA/cm2 to nA
   			loc.sec mean = 1e-5 * mean * area(0.5)
			
 			loc.sec	sd   = 1e-5 * sd   * area(0.5)
 			
   		//	loc.sec print secname(), " mena=", mean, " sd=", sd 
   		}else{
   		// otherwise mean and sd are in pA, and need to be converted to nA
   			mean = 1e-3 * mean
   			sd   = 1e-3 * sd
   			//loc.sec print secname(), " mean=", mean, " sd=", sd 
   		}
        
        rD       = new Random((startsw()+$4)%10000)
        
        iappR.del     = 0 //rD.uniform(0, 750) //###changed to 0 7/8/8
        iappR.dur     = 1e9
        
        //loc.sec print secname(), iappR.del
        
        rR = new Random((startsw()*$4)%10000)
        rR.normal(mean, sd*sd)
        rR.play(&iappR.amp)
}




// =================================================================================================
//
// set_random()
//
// ================================================================================================= 
proc set_random() {
   
        rC       = new Random((startsw()+$1)%10000)
        iapp.dur = rC.uniform(0, 500)      
        iapp.del = 0
        loc.sec iapp.amp = rC.uniform(-5, 5) * area(0.5) * 1e-5
        //print "amp: ", iappR.amp, secname(), $1
}




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




// =================================================================================================
//
// get()
//
// ================================================================================================= 
proc get() {
    loc.sec printf("iapp = %g (nA), loc= %s\n", iapp.amp, secname())
}

endtemplate IApp

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