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Dendro-dendritic synaptic circuit (Shepherd Brayton 1979)
Accession: 144385
A NEURON simulation has been created to model the passive spread of an EPSP from a mitral cell synapse on a granule cell spine. The EPSP was shown to propagate subthreshold through the dendritic shaft into an adjacent spine with significant amplitude (figure 2B).
Reference: Shepherd GM, Brayton RK (1979) Computer simulation of a dendrodendritic synaptic circuit for self- and lateral-inhibition in the olfactory bulb. Brain Res 175:377-82 [PubMed]
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Model Information (Click on a link to find other models with that property)
Model Type:  Dendrite;
Brain Region(s)/Organism:  
Cell Type(s):   
Channel(s):   
Gap Junctions:  
Receptor(s):  
Gene(s):  
Transmitter(s):  
Simulation Environment:  Neuron;
Model Concept(s):  Influence of Dendritic Geometry;
Implementer(s):  Morse, Tom [Tom.Morse at Yale.edu];
\
ShepherdBrayton1979
hoc
mod
mrf
traces2vecs
readme.html
modified_params_screenshot.jpg
mosinit.hoc
init.hoc
                            
This is the readme for NEURON code developed to reproduce Fig 2B from

Shepherd GM, Brayton RK (1979) Computer simulation of a
dendrodendritic synaptic circuit for self- and lateral-inhibition in
the olfactory bulb. Brain Res 175:377-82

There were typos in Figure 1 (Shepherd, private communication) where
the granule cell spine geometry should have been specified as 3 micron
length, 1 micron diameter head and 1 micron length and 0.2 micron
width neck dimensions.  The granule cell compartments were 70 microns
in length and 1 micron in diameter.

The NEURON models cytoplasmic and membrane resistance, Ri, and Rm, as
well as the excitatory synaptic conductance pulse (a trapezoidal
pulse) were optimized to the original paper Fig 2B:

Modified model screenshot

The above screenshot includes (black lines) that were the
result of using manually traced original curves:

Shepherd & Brayton 1979

Usage: Auto-launch from ModelDB or download, extract the archive and
compile the mod files in the mod directory by either

typing "nrnivmodl mod" (linux), 
running mknrndll and cd'ing to the mod folder (mswin), or
dragging and dropping the mod folder onto the mknrndll icon (Mac OS X)

Then start with
nrngui mosinit.hoc (linux),
double clicking the mosinit.hoc file in windows explorer (mswin), or
dragging and dropping the mosinit.hoc file on the nrngui icon (Mac OS X).

Once the simulation has started you can either 

1) optimize to find the Ri, Rm, and conductance pulse trapezoidal
shape that matches the paper: On the multiple run fitter window click
on Parameters -> Select Optimizer -> Praxis, and then click on the
Optimize button in the "MulRunFitter[0] Optimize" box.
After a short time praxis will find the Ri ~ 90 and Rm ~ 1300.

2) or use a previously saved Multiple Run Fitter session to see the
result of optimizing. Close the MulRunFitter[0] main window and select
from the NEURON main menu: File -> load session file, and then using
the popped up file picker, browse to the mrf folder and select
mrf5.ses, which contains the result of a previous optimization.  Now
you can press the ErrorValue button on the newly opened MulRunFitter
window to generate a run.  The graphs will be refreshed with optimized
voltage trajectories.

For questions, please contact Tom.Morse at yale.edu.

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