Amyloid-beta effects on release probability and integration at CA3-CA1 synapses (Romani et al. 2013)

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Accession:147757
The role of amyloid beta (Aß) in brain function and in the pathogenesis of Alzheimer’s disease remains elusive. Recent publications reported that an increase in Aß concentration perturbs presynaptic release in hippocampal neurons, in particular by increasing release probability of CA3-CA1 synapses. The model predics how this alteration can affect synaptic plasticity and signal integration. The results suggest that the perturbation of release probability induced by increased Aß can significantly alter the spike probability of CA1 pyramidal neurons and thus contribute to abnormal hippocampal function during Alzheimer’s disease.
Reference:
1 . Romani A, Marchetti C, Bianchi D, Leinekugel X, Poirazi P, Migliore M, Marie H (2013) Computational modeling of the effects of amyloid-beta on release probability at hippocampal synapses. Front Comput Neurosci 7:1 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Neuron or other electrically excitable cell; Synapse;
Brain Region(s)/Organism: Hippocampus;
Cell Type(s): Hippocampus CA1 pyramidal GLU cell;
Channel(s): I Na,t; I A; I K; I M; I h; I Calcium; I_AHP;
Gap Junctions:
Receptor(s): AMPA;
Gene(s):
Transmitter(s): Glutamate;
Simulation Environment: NEURON;
Model Concept(s): Synaptic Plasticity; Short-term Synaptic Plasticity; Facilitation; Depression; Synaptic Integration; Aging/Alzheimer`s;
Implementer(s): Bianchi, Daniela [danielabianchi12 -at- gmail.com]; Romani, Armando [romani.armando -at- gmail.com];
Search NeuronDB for information about:  Hippocampus CA1 pyramidal GLU cell; AMPA; I Na,t; I A; I K; I M; I h; I Calcium; I_AHP; Glutamate;
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RomaniEtAl2013
experiment
cad.mod *
cagk.mod *
cal.mod *
calH.mod *
car.mod *
cat.mod *
d3.mod *
h.mod *
kadist.mod *
kaprox.mod *
kca.mod *
kdr.mod *
km.mod *
na3.mod *
na3dend.mod *
na3notrunk.mod *
nap.mod *
nax.mod *
netstimmm.mod *
somacar.mod *
tmgsyn.mod
vecevent.mod
cell-setup.hoc
createNewSyn4.hoc
loadBasicModel.hoc
mosinit.hoc
session.ses
simulation.hoc
                            
TITLE Ca R-type channel with medium threshold for activation
: used in somatic regions. It has lower threshold for activation/inactivation
: and slower activation time constant
: than the same mechanism in dendritic regions
: uses channel conductance (not permeability)
: written by Yiota Poirazi on 3/12/01 poirazi@LNC.usc.edu

NEURON {
	SUFFIX somacar
	USEION ca READ eca WRITE ica
        RANGE gcabar, m, h
	RANGE inf, fac, tau
}

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



PARAMETER { 
        eca = 140       (mV)      : Ca++ reversal potentia    
        gcabar = 0      (mho/cm2) : initialized conductance
        celsius =34        (degC)
}


ASSIGNED {      : parameters needed to solve DE
        v               (mV)
 	ica             (mA/cm2)
	ecar             (mV)      : Ca++ reversal potential
        inf[2]
	fac[2]
	tau[2]
       : cai		(mM)
        :cao		(mM)
}

STATE {	
	m 
	h 
} 


INITIAL {
	m = 0    : initial activation parameter value
	h = 1    : initial inactivation parameter value
	rates(v)
      ica = gcabar*m*m*m*h*(v - eca)  : initial Ca++ current value
}

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


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


PROCEDURE rates(v(mV)) {
	FROM i=0 TO 1 {
		tau[i] = vartau(i)
		inf[i] = varss(v,i)
	}
}



FUNCTION varss(v(mV), i) {
	if (i==0) {
	   varss = 1 / (1 + exp((v+60)/(-3))) :Ca activation
	}
	else if (i==1) {
           varss = 1/ (1 + exp((v+62)/(1)))   :Ca inactivation
	}
}

FUNCTION vartau(i) {
	if (i==0) {
           vartau = 100  : activation variable time constant
        }
	else if (i==1) {
           vartau = 5    : inactivation variable time constant
       }
	
}	

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