TC-neuron model, Geir Halnes, january 2013

Point model, with three ion channels: Nax, Kdr, It
Can burst or fire tonically. 


A TC-neuron model previously published by Destexhe et al. 
was downloaded from ModelDB: 
http://senselab.med.yale.edu/modeldb/ShowModel.asp?model=3343

The previous model simulated thalamic oscillations in a network
of thalamocortical neurons and thalamic reticular cells.
(See README by Destexhe attached below.) 

Here, the TC-model was simplified, and parameters were ajusted.
The Destexhe-model was focused around oscillations. It gave
single neuron properties that I don't think are typical,
such as strong Ca-oscillations around resting pot.

Only the It-channel, and the AP-generalting Nax and Kdr was kept.
It-conductance was reduced to get rid of Ca-oscillations around rest.
AP-firing threshold was adjusted to some reasonable value. 
Nax/Kdr conductances were reduced, to get more realistic spike-shapes.

The TCN has two typical resting states.
With e_pas = -84mV, the resting pot. is around -69mV. The neuron responds
to input by tonic AP-firing.
With e_pas = -87mV, the resting pot. is around -80mV. The neurons responds
ro input by a burst, followed by tonic AP-firing.

The huge difference in V_rest stems from It being active around rest (e_pas and it compete).


P.s. 
We might find later use of the GABA synapses from Destexhe et al.





//////

    NEURON TUTORIAL FOR IMPLEMENTING SIMULATIONS OF THALAMIC OSCILLATIONS

                          Alain Destexhe
		Laboratory for Computational Neuroscience
	Unité de Neurosciences Intégratives et Computationnelles (UNIC)
	Centre National de la Recherche Scientifique (CNRS)
			91198 Gif-sur-Yvette, France 

	    Formerly from (when this work was created):
            Department of Physiology, Laval University,
                      Quebec G1K 7P4, Canada

                       Destexhe@iaf.cnrs-gif.fr
                     http://cns.iaf.cnrs-gif.fr/Main.html


This package is running with the NEURON simulation program written by Michael
Hines and available on internet at:
  http://www.neuron.yale.edu/neuron/
  http://neuron.duke.edu/

The package contains mechanisms (.mod files) and programs (.oc files) needed 
to simulate interconnected thalamocortical (TC) and thalamic reticular (RE) 
cells, relative to the paper:

  Destexhe, A., Bal, T., McCormick, D.A. and Sejnowski, T.J.
  Ionic mechanisms underlying synchronized oscillations and propagating
  waves in a model of ferret thalamic slices. Journal of Neurophysiology
  76: 2049-2070, 1996. 

A postscript version of this paper, including figures, is available on
internet at 
  http://cns.iaf.cnrs-gif.fr/Main.html
  
  PROGRAMS
  ========

 Fspin.oc	: spindle oscillations (short run)
			  see Fig. 7 of the paper
 FspinL.oc	: spindle oscillations (long run)
			  see Fig. 7 of the paper
 Fbic.oc	: bicuculline-induced oscillations (short run)
			  see Fig. 8 of the paper
 FbicL.oc	: bicuculline-induced oscillations (long run)
			  see Fig. 8 of the paper
 Fdelta.oc	: delta oscillations (short run)
 FdeltaL.oc	: delta oscillations (long run)



  MECHANISMS
  ==========

 HH2.mod		: fast sodium spikes (Na and K currents)
 IT.mod			: T-current for TC cell
 IT2.mod		: T-current for RE cell (different kinetics and v-dep)
 Ih.mod			: h-current for TC cell, including upregulation
			  by intracellular calcium
 cadecay.mod		: intracellular calcium dynamics
 kleak.mod		: leak K+ current (TC cell)

 ampa.mod		: AMPA-mediated synaptic currents
 gabaa.mod		: GABA_A-mediated synaptic currents
 gabab.mod		: GABA_B-mediated synaptic currents


  HOW TO RUN
  ==========

Use autolaunch on modeldb or:

unix platform:

To compile the demo, NEURON and INTERVIEWS must be installed and working on
the machine you are using.  Just type "nrnivmodl" to compile the mechanisms
given in the mod files.

Then, execute the main demo program by typing:

  nrngui mosinit.hoc

mswin platform:

  Compile the mechanism (mod) files by using mknrndll.  Then start the simulation
  by clicking on mosinit.hoc in windows explorer.

back to any platform:

Once the menu and graphics interface has appeared, select a simulation from the
"Simulations of thalamic oscillations" window.  Then click on "Init and Run"
button to start the simulation...

For more information about how to get NEURON and how to install it, please
refer to the following sites:
  http://neuron.duke.edu/
  http://www.neuron.yale.edu/

For further information, please contact:

Alain Destexhe
Laboratory for Computational Neuroscience
Unité de Neurosciences Intégratives et Computationnelles (UNIC)
Centre National de la Recherche Scientifique (CNRS)
91198 Gif-sur-Yvette, France 

Destexhe@iaf.cnrs-gif.fr
http://cns.iaf.cnrs-gif.fr/Main.html

7/11/2005 Additional modifications to restart by first closing other simulation
windows and also updating README contact information.

2/14/2001 Michael Hines trivially modified some of the hoc files
to use the more flexible load_file in place of certain xopen statements,
ensure that the current version of the standard gui library comes
up first, and arrange graphs on the screen.

Not yet:
He also updated the mod files to be compatible with cvode and
make use of internal compuations of ionic reversal potential. This
version is quantitatively identical to the original.

10-2007: AD, better synaptic mechanisms using counters; added delta
oscillations.