Spike frequency adaptation in spinal sensory neurones (Melnick et al 2004)

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Accession:62284
Using tight-seal recordings from rat spinal cord slices, intracellular labelling and computer simulation, we analysed the mechanisms of spike frequency adaptation in substantia gelatinosa (SG) neurones. Adapting-firing neurones (AFNs) generated short bursts of spikes during sustained depolarization and were mostly found in lateral SG. ... Ca2 + -dependent conductances do not contribute to adapting firing. Transient KA current was small and completely inactivated at resting potential suggesting that adapting firing was mainly generated by voltage-gated Na+ and delayed-rectifier K+ (KDR ) currents. ... Computer simulation has further revealed that down-regulation of Na+ conductance represents an effective mechanism for the induction of firing adaptation. It is suggested that the cell-specific regulation of Na+ channel expression can be an important factor underlying the diversity of firing patterns in SG neurones. See paper for more and details.
Reference:
1 . Melnick IV, Santos SF, Safronov BV (2004) Mechanism of spike frequency adaptation in substantia gelatinosa neurones of rat. J Physiol 559:383-95 [PubMed]
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):
Channel(s):
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Short-term Synaptic Plasticity; Spike Frequency Adaptation;
Implementer(s): Safronov, Boris [safronov at ibmc.up.pt];
xopen("$(NEURONHOME)/lib/hoc/noload.hoc")
pwman_place(20,21)
ndend=1
create soma, hillock, axon, dend[ndend]


access soma
{diam=10 L=10 nseg=10} // area 100 um2 means mA/cm2 identical to nA 
insert B_Na
insert B_A
insert B_DR
insert KDR
insert KDRI
insert pas

access hillock
{L=3 nseg=30 dsoma=1 daxon=0.5 diam(0:1)=dsoma:daxon}
insert B_Na
insert B_A
insert B_DR
insert KDR
insert KDRI
insert pas

access axon
{diam=0.5 L=25 nseg=50}
insert B_Na
insert B_A
insert B_DR
insert KDR
insert KDRI
insert pas

for i=0, ndend-1 dend[i] {
	nseg=50
	diam=4
//	diam(0.43:1) = 4:0  // tapering of the distal dendrite
	L=1000
//insert B_Na
insert SS
insert B_DR
insert KDR
insert KDRI	
insert pas
}

soma connect hillock(0),1
hillock connect axon(0),1
for i=0,ndend-1 soma connect dend[i](0),0 

{
//load_proc("nrnmainmenu")
load_file("electrod.hoc")
//load_template("Electrode")
//load_template("MenuExplore")
//load_template("PointProcessLocator")
//load_template("ShowMechanism")
//load_template("Inserter")
//load_template("PointProcessManager")


//xopen("$(NEURONHOME)/Demo/ba/adapting1.ses")
xopen("adapting1.ses")
forall Ra=80
}

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