Linear vs non-linear integration in CA1 oblique dendrites (Gómez González et al. 2011)

 Download zip file   Auto-launch 
Help downloading and running models
Accession:144450
The hippocampus in well known for its role in learning and memory processes. The CA1 region is the output of the hippocampal formation and pyramidal neurons in this region are the elementary units responsible for the processing and transfer of information to the cortex. Using this detailed single neuron model, it is investigated the conditions under which individual CA1 pyramidal neurons process incoming information in a complex (non-linear) as opposed to a passive (linear) manner. This detailed compartmental model of a CA1 pyramidal neuron is based on one described previously (Poirazi, 2003). The model was adapted to five different reconstructed morphologies for this study, and slightly modified to fit the experimental data of (Losonczy, 2006), and to incorporate evidence in pyramidal neurons for the non-saturation of NMDA receptor-mediated conductances by single glutamate pulses. We first replicate the main findings of (Losonczy, 2006), including the very brief window for nonlinear integration using single-pulse stimuli. We then show that double-pulse stimuli increase a CA1 pyramidal neuron’s tolerance for input asynchrony by at last an order of magnitude. Therefore, it is shown using this model, that the time window for nonlinear integration is extended by more than an order of magnitude when inputs are short bursts as opposed to single spikes.
Reference:
1 . Gómez González JF, Mel BW, Poirazi P (2011) Distinguishing Linear vs. Non-Linear Integration in CA1 Radial Oblique Dendrites: It's about Time. Front Comput Neurosci 5:44 [PubMed]
Citations  Citation Browser
Model Information (Click on a link to find other models with that property)
Model Type: Neuron or other electrically excitable cell;
Brain Region(s)/Organism:
Cell Type(s): Hippocampus CA1 pyramidal GLU cell;
Channel(s): I Na,p; I CAN; I Sodium; I Calcium; I Potassium; I_AHP;
Gap Junctions:
Receptor(s): NMDA;
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Active Dendrites; Detailed Neuronal Models; Synaptic Integration;
Implementer(s):
Search NeuronDB for information about:  Hippocampus CA1 pyramidal GLU cell; NMDA; I Na,p; I CAN; I Sodium; I Calcium; I Potassium; I_AHP;
/
CA1_Gomez_2011
mechanism
x86_64
ampa.mod *
cad.mod
cal.mod
calH.mod
can.mod *
car.mod
cat.mod
d3.mod *
gabaa.mod *
gabab.mod
h.mod
hha_old.mod
hha2.mod
ican.mod
ipulse1.mod *
ipulse2.mod *
kadist.mod
kaprox.mod
kca.mod
kct.mod
KdBG.mod
km.mod
nap.mod *
netstim.mod *
netstimmm.mod *
nmda.mod *
NMDAb.mod
somacar.mod
                            
TITLE Ca R-type channel with medium threshold for activation
: used in distal dendritic regions, together with calH.mod, to help
: the generation of Ca++ spikes in these regions
: uses channel conductance (not permeability)
: written by Yiota Poirazi on 11/13/00 poirazi@LNC.usc.edu
:
: updated to use CVode by Carl Gold 08/10/03
:  Updated by Maria Markaki  03/12/03

NEURON {
	SUFFIX car
	USEION ca READ cai, cao WRITE ica
:	USEION Ca WRITE iCa VALENCE 2
        RANGE gcabar, m, h,ica
	RANGE inf, fac, tau
}

UNITS {
	(mA) = (milliamp)
	(mV) = (millivolt)
	(molar) = (1/liter)
	(mM) =	(millimolar)
	FARADAY = (faraday) (coulomb)
	R = (k-mole) (joule/degC)
}


ASSIGNED {               : parameters needed to solve DE
	ica (mA/cm2)
:	iCa (mA/cm2)
        inf[2]
	tau[2]		(ms)
        v               (mV)
        celsius 	(degC)
	ecar    	(mV)      
	cai             (mM)      : initial internal Ca++ concentration
	cao             (mM)      : initial external Ca++ concentration
}


PARAMETER {              : parameters that can be entered when function is called in cell-setup
        gcabar = 0      (mho/cm2) : initialized conductance
}  

STATE {	
	m 
	h 
}            : unknown activation and inactivation parameters to be solved in the DEs  


INITIAL {
	rates(v)
        m = 0    : initial activation parameter value
	h = 1    : initial inactivation parameter value
}

BREAKPOINT {
	SOLVE states METHOD cnexp
	ecar = (1e3) * (R*(celsius+273.15))/(2*FARADAY) * log (cao/cai)
	ica = gcabar*m*m*m*h*(v - ecar)
:	iCa = gcabar*m*m*m*h*(v - ecar)

}


DERIVATIVE states {
	rates(v)
	m' = (inf[0]-m)/tau[0]
	h' = (inf[1]-h)/tau[1]
}

PROCEDURE rates(v(mV)) {LOCAL a, b :rest = -70
	FROM i=0 TO 1 {
		tau[i] = vartau(v,i)
		inf[i] = varss(v,i)
	}
}




FUNCTION varss(v(mV), i) {
	if (i==0) {
	    varss = 1 / (1 + exp((v+48.5)/(-3(mV)))) : Ca activation
	}
	else if (i==1) {
             varss = 1/ (1 + exp((v+53)/(1(mV))))    : Ca inactivation
	}
}

FUNCTION vartau(v(mV), i) (ms){
	if (i==0) {
:          vartau = 50(ms)  : activation variable time constant
          vartau = 120(ms)  : activation variable time constant
        }
	else if (i==1) {
:           vartau = 5(ms)   : inactivation variable time constant
           vartau = 4(ms)   : inactivation variable time constant
       }
	
}