CA1 pyramidal neurons: binding properties and the magical number 7 (Migliore et al. 2008)

 Download zip file   Auto-launch 
Help downloading and running models
Accession:87535
NEURON files from the paper: Single neuron binding properties and the magical number 7, by M. Migliore, G. Novara, D. Tegolo, Hippocampus, in press (2008). In an extensive series of simulations with realistic morphologies and active properties, we demonstrate how n radial (oblique) dendrites of these neurons may be used to bind n inputs to generate an output signal. The results suggest a possible neural code as the most effective n-ple of dendrites that can be used for short-term memory recollection of persons, objects, or places. Our analysis predicts a straightforward physiological explanation for the observed puzzling limit of about 7 short-term memory items that can be stored by humans.
Reference:
1 . Migliore M, Novara G, Tegolo D (2008) Single neuron binding properties and the magical number 7. Hippocampus 18(11):1122-30 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Dendrite;
Brain Region(s)/Organism:
Cell Type(s): Hippocampus CA1 pyramidal cell;
Channel(s): I A; I K; I h; I Sodium;
Gap Junctions:
Receptor(s): AMPA;
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Pattern Recognition; Activity Patterns; Dendritic Action Potentials; Coincidence Detection; Spatio-temporal Activity Patterns; Active Dendrites; Detailed Neuronal Models; Action Potentials; Synaptic Integration; Working memory; Learning; Action Selection/Decision Making;
Implementer(s): Migliore, Michele [Michele.Migliore at Yale.edu];
Search NeuronDB for information about:  Hippocampus CA1 pyramidal cell; AMPA; I A; I K; I h; I Sodium;
/
magical7
readme.txt
h.mod *
kadist.mod *
kaprox.mod *
kdrca1.mod *
na3n.mod *
naxn.mod *
netstims.mod *
2ap-distr-c62564AP.hoc
face.exe *
fixnseg.hoc *
geoc62564.hoc *
mosinit.hoc
Project1.exe *
sinapsi_weights.txt
                            
TITLE K-A channel from Klee Ficker and Heinemann
: modified to account for Dax A Current ----------
: M.Migliore Jun 1997

UNITS {
        (mA) = (milliamp)
        (mV) = (millivolt)
}

PARAMETER {
	celsius
        v (mV)
        gkabar=.008 (mho/cm2)
        vhalfn=-1   (mV)
        vhalfl=-56   (mV)
        a0l=0.05      (/ms)
        a0n=.1    (/ms)
        zetan=-1.8    (1)
        zetal=3    (1)
        gmn=0.39   (1)
        gml=1   (1)
        lmin=2  (mS)
        nmin=0.2  (mS)
        pw=-1    (1)
        tq=-40
        qq=5
        q10=5
        qtl=1
	ek
}


NEURON {
        SUFFIX kad
        USEION k READ ek WRITE ik
        RANGE gkabar,gka
        GLOBAL ninf,linf,taul,taun,lmin
}

STATE {
        n
        l
}

ASSIGNED {
        ik (mA/cm2)
        ninf
        linf      
        taul
        taun
        gka
}

BREAKPOINT {
        SOLVE states METHOD cnexp
        gka = gkabar*n*l
        ik = gka*(v-ek)

}

INITIAL {
	rates(v)
	n=ninf
	l=linf
}


FUNCTION alpn(v(mV)) {
LOCAL zeta
  zeta=zetan+pw/(1+exp((v-tq)/qq))
  alpn = exp(1.e-3*zeta*(v-vhalfn)*9.648e4/(8.315*(273.16+celsius))) 
}

FUNCTION betn(v(mV)) {
LOCAL zeta
  zeta=zetan+pw/(1+exp((v-tq)/qq))
  betn = exp(1.e-3*zeta*gmn*(v-vhalfn)*9.648e4/(8.315*(273.16+celsius))) 
}

FUNCTION alpl(v(mV)) {
  alpl = exp(1.e-3*zetal*(v-vhalfl)*9.648e4/(8.315*(273.16+celsius))) 
}

FUNCTION betl(v(mV)) {
  betl = exp(1.e-3*zetal*gml*(v-vhalfl)*9.648e4/(8.315*(273.16+celsius)))
 
}

DERIVATIVE states {  
        rates(v)
        n' = (ninf - n)/taun
        l' = (linf - l)/taul
}

PROCEDURE rates(v (mV)) { :callable from hoc
        LOCAL a,qt
        qt=q10^((celsius-24)/10)
        a = alpn(v)
        ninf = 1/(1 + a)
        taun = betn(v)/(qt*a0n*(1+a))
        if (taun<nmin) {taun=nmin}
        a = alpl(v)
        linf = 1/(1+ a)
        taul = 0.26*(v+50)/qtl
        if (taul<lmin/qtl) {taul=lmin/qtl}
}


Loading data, please wait...