ModelDB: CA1 pyramidal cell: reconstructed axonal arbor and failures at weak gap junctions (Vladimirov 2011)

CA1 pyramidal cell: reconstructed axonal arbor and failures at weak gap junctions (Vladimirov 2011)

Accession: 144401

Model of pyramidal CA1 cells connected by gap junctions in their axons. Cell geometry is based on anatomical reconstruction of rat CA1 cell (NeuroMorpho.Org ID: NMO_00927) with long axonal arbor. Model init_2cells.hoc shows failures of second spike propagation in a spike doublet, depending on conductance of an axonal gap junction. Model init_ring.hoc shows that spike failure result in reentrant oscillations of a spike in a loop of axons connected by gap junctions, where one gap junction is weak. The paper shows that in random networks of axons connected by gap junctions, oscillations are driven by single pacemaker loop of axons. The shortest loop, around which a spike can travel, is the most likely pacemaker. This principle allows us to predict the frequency of oscillations from network connectivity and visa versa. We propose that this type of oscillations corresponds to so-called fast ripples in epileptic hippocampus.
Reference: Vladimirov N, Tu Y, Traub RD (2012) Shortest loops are pacemakers in random networks of electrically coupled axons Frontiers in Computational Neuroscience 6:17 [PubMed]

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Model Information (Click on a link to find other models with that property)

Model Type:	Network; Axon;
Brain Region(s)/Organism:	Hippocampus;
Cell Type(s):	CA1 pyramidal neuron;
Channel(s):	I Na,t; I A; I K; I M; I K,Ca; I Calcium; I Potassium;
Gap Junctions:	Gap junctions;
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment:	Neuron;
Model Concept(s):	Oscillations; Axonal Action Potentials; Epilepsy; Conduction failure;
Implementer(s):	Vladimirov, Nikita ;

Search NeuronDB for information about: CA1 pyramidal neuron; I Na,t; I A; I K; I M; I K,Ca; I Calcium; I Potassium;

Model files

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VladimirovTuTraub2012

Model of pyramidal CA1 cells connected by gap junctions in their axons.

Cell geometry is based on anatomical reconstruction of rat CA1 cell
(NeuroMorpho.Org ID: NMO_00927) with long axonal arbor.
Model init_2cells.hoc shows failures of second spike propagation in a
spike doublet, depending on conductance of an axonal gap junction.
Model init_ring.hoc shows that spike failure result in reentrant
oscillations of a spike in a loop of axons connected by gap junctions,
where one gap junction is weak.
See N. Vladimirov, Y. Tu, R.D. Traub. Shortest loops are pacemakers in
random networks of electrically coupled axons.
Front. Comput. Neurosci. 6:17. doi: 10.3389/fncom.2012.00017.

Usage
1. Unzip Vladimirov2012.zip into an empty directory
2. Compile the mod files with nrnivmodl or mknrndll
3. Double click on init_2cells.hoc, or execute
nrngui init_2cells.hoc
from the command line
4. Panels will appear with RunControl buttons, graph of voltage in
axons, and cell shapes including a graph of the axon morphology:



5. Click "Init & Run" button to start the simulation.  After a short
time you should see a graph of the APs:



6) Do steps 3-5 with double click on init_ring.hoc, or execute
nrngui init_ring.hoc
to simulate how failure of second spike in a doublet results in
reentrant spike in the loop.



Implemented by Nikita Vladimirov [nikita.vladimirov at gmail.com]

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