CA1 pyramidal neuron: Persistent Na current mediates steep synaptic amplification (Hsu et al 2018)

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This paper shows that persistent sodium current critically contributes to the subthreshold nonlinear dynamics of CA1 pyramidal neurons and promotes rapidly reversible conversion between place-cell and silent-cell in the hippocampus. A simple model built with realistic axo-somatic voltage-gated sodium channels in CA1 (Carter et al., 2012; Neuron 75, 1081–1093) demonstrates that the biophysics of persistent sodium current is sufficient to explain the synaptic amplification effects. A full model built previously (Grienberger et al., 2017; Nature Neuroscience, 20(3): 417–426) with detailed morphology, ion channel types and biophysical properties of CA1 place cells naturally reproduces the steep voltage dependence of synaptic responses.
1 . Hsu CL, Zhao X, Milstein AD, Spruston N (2018) Persistent sodium current mediates the steep voltage dependence of spatial coding in hippocampal pyramidal neurons Neuron 99:1-16
Model Information (Click on a link to find other models with that property)
Model Type: Synapse; Channel/Receptor; Neuron or other electrically excitable cell; Axon; Dendrite;
Brain Region(s)/Organism: Hippocampus;
Cell Type(s): Hippocampus CA1 pyramidal GLU cell; Abstract single compartment conductance based cell;
Channel(s): I Sodium; I A; I M; I h; I K;
Gap Junctions:
Receptor(s): AMPA; NMDA;
Transmitter(s): Glutamate;
Simulation Environment: NEURON;
Model Concept(s): Ion Channel Kinetics; Membrane Properties; Synaptic Integration; Synaptic Amplification; Place cell/field; Active Dendrites; Conductance distributions; Detailed Neuronal Models; Electrotonus; Markov-type model;
Implementer(s): Hsu, Ching-Lung [hsuc at]; Milstein, Aaron D. [aaronmil at];
Search NeuronDB for information about:  Hippocampus CA1 pyramidal GLU cell; AMPA; NMDA; I A; I K; I M; I h; I Sodium; Glutamate;
ampa_kin.mod *
gaba_a_kin.mod *
kad.mod *
kap.mod *
kdr.mod *
nmda_kin5.mod *
pr.mod *
vecevent.mod *
install notes.txt
I) To install on a local machine:

1) install anaconda python, includes ipython, numpy, matplotlib

2) clone neuron github repositories:
mkdir ~/neuron
cd ~/neuron
git clone
cd nrn
cd ..
git clone
cd iv

Install following tips from:

3) Install btmorph from

4) Make sure ~/neuron/nrnenv includes:

export IDIR=$HOME/neuron
export IV=$IDIR/iv
export N=$IDIR/nrn
export CPU=x86_64
export PATH=$IV/$CPU/bin:$N/$CPU/bin:$PATH

and ~/.bash_profile includes:

export PATH=$HOME/anaconda/bin:$PATH
export PATH=$HOME/local/bin:$PATH
source $HOME/neuron/nrnenv
export PATH=$HOME/neuron:$PATH
export PYTHONPATH=$HOME/neuron/nrn/lib/python:$PYTHONPATH
export PYTHONPATH=$HOME/python_modules/btmorph:$PYTHONPATH

5) If error related to libreadline.6.2.dylib :

cd ~/neuron/nrn/lib/python/neuron/
install_name_tool -change libreadline.6.2.dylib $HOME/anaconda2/lib/libreadline.6.2.dylib

6) On a linux cluster, may need to set the default backend for matplotlib to 'Agg' in the matplotlibrc file so that
importing pyplot doesn't cause errors in a system without display capability.

Original config file should be in site-packages/matplotlib/mpl-data/matplotlibrc
Copy it to $HOME/.config/matplotlib/matplotlibrc, then change the backend to 'Agg'.

On my mac, I have to manually edit matplotlibrc in site-packages/matplotlib/mpl-data to
'Qt5Agg' every time I update anaconda.

7) To run NEURON simulations, make sure to execute nrnivmodl in the directory that contains the .mod and .py files.
Make sure to put .swc files in the /morphologies directory and expect to find .pkl and .hdf5 data output files in the
/data directory

Then start an iPython session with: ipython

and execute pieces of the similation with:
run name_of_py_file

build your own cell with

from specify_cells import *

cell = HocCell()

You can also import a morphology from an .swc file:

cell = HocCell('str_with_name_of_swc_file.swc')

BtMorph requires that the compartments with indices 1, 2, and 3 all be of type 1 (soma), according to the standard used
by . My model expects compartment types to be labeled as follows
(1 = soma, 2 = axon, 3 = basal, 4 = apical, 5 = trunk, 6 = tuft).
Soma and axon compartments are discarded and replaced with a simplified representation of soma and axon.

Ion channel mechanisms and cable parameters for various types of compartments can be inserted with commands like:

cell.modify_mech_param('soma', 'cable', 'Ra', 150.)
cell.modify_mech_param('soma', 'pas', 'g', 0.0002)
cell.modify_mech_param('basal', 'h', 'ghbar', origin='soma')
cell.modify_mech_param(sec_type, 'kap', 'gkabar', origin='soma', slope=3.84e-4, max=0.24)

Once you have a cell appropriately specified, you can save a file containing the mechanisms with:

cell.export_mech_dict('str_with_name_of_pkl_file.pkl'), or with no arg to automatically generate a unique filename with
the data and timestamp.

Then a cell can be instantiated with a mech_dict file:

cell = HocCell('str_with_name_of_swc_file.swc', 'str_with_name_of_pkl_file.pkl')

plot functions can be executed following:
from plot_results import *

A quick simulation using adaptive timestep integration can be run with:

sim = QuickSim(duration)
sim.append_rec(cell, cell.tree.root, loc=0.5, description='soma')


sim.export_to_file(name_of_hdf5_object, index_of_similation_in_file)

then calling a plot function on the output file:

plot_superimpose_conditions('str_with_name_of_output_file') # no suffix necessary

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