AP shape and parameter constraints in optimization of compartment models (Weaver and Wearne 2006)

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"... We construct an objective function that includes both time-aligned action potential shape error and errors in firing rate and firing regularity. We then implement a variant of simulated annealing that introduces a recentering algorithm to handle infeasible points outside the boundary constraints. We show how our objective function captures essential features of neuronal firing patterns, and why our boundary management technique is superior to previous approaches."
1 . Weaver CM, Wearne SL (2006) The role of action potential shape and parameter constraints in optimization of compartment models Neurocomputing 69:1053-1057
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): Vestibular neuron;
Channel(s): I Na,p; I Na,t; I A; I K,Ca;
Gap Junctions:
Simulation Environment: NEURON;
Model Concept(s): Parameter Fitting; Methods;
Implementer(s): Weaver, Christina [christina.weaver at fandm.edu];
Search NeuronDB for information about:  I Na,p; I Na,t; I A; I K,Ca;
This directory includes a demonstration of the fitness function 
and optimization method described in

    Weaver, CM and Wearne, SL.  The role of action potential shape
    and parameter constraints in optimization of compartment models.
    Neurocomputing 69: 1053-1057, (2006).

I.  To run this demo:

Either Auto-launch from ModelDB or 
1) download and extract the archive.
2) Then under

unix/linux: type the following at the command line:

	cd weaver_SimAnn_ObjFcn
	nrnivmodl model optmz
	nrngui mosinit.hoc

mswin: start nrngui (from the start button ->Programs -> NEURON 5.9
       for example) then File -> working dir to first the model
       directory and then File -> working dir to the optmz directory.
       Then you can File -> load hoc and select mosinit.hoc.

mac OS X: running under mac is under development

Once the model is running you can press the "Testing Shapes" windows
buttons (e.g. "Matched to Target", etc.) to select alternate initial

A.  Different Objective Functions

This demo evaluates the difference betweeen model and target data by
two different functions, specified under the Multiple Run Fitter

(1) RegionFitness, i.e. mean squared error between voltage traces
(2) APShpFRCVFitness: a linear combination of the errors in
    time-aligned AP shape, mean FR, and irregularity measured by the
    CV.  (See Weaver and Wearne reference above).  The weights of each
    component can be changed by displaying the APShpFRCVFitness
    generator, then choosing Select, followed by the appropriate
    drop-down menu choice.

Click on one of the buttons to the left.  This will initialize the
model, run it, and evaluate the error between that model and the
target data shown in the MRF windows.

Summary data are written to matlab files (.m extension) that print the
model and target voltage traces, plus a summary of the AP Shape / FR /
CV error.  The name of this output file can be changed by bringing up
the appropriate MRF Generator and choosing Select -> Set output info.

B.  Simulated annealing for parameter optimization

   If you go to the MRF window and choose Parameters -> Select
   Optimizer, there are two new options:

    - Simulated Annealing
    - Constrained Simulated Annealing with Recentering

    The first, implemented by Andrew Davison, performs the
    Simplex-based simulated annealing optimization algorithm found in
    Numerical Recipes in C.

    The second, implemented by Christina Weaver, performs a version of
    this algorithm that incorporates constraints on the parameters to
    be optimized.  See Weaver and Wearne (2006) for details, and for
    the original reference (Cardoso et al. 1996) which introduced this
    algorithm.  See the enclosed PDF help file for details of this
    NEURON implementation.

    In addition to a new set of Optimizer menu items specific to these
    optimization techniques, one change has been made to the general
    MRF Optimize menu.  In the past the output from a parameter search
    was always output to the same filename, so that one would often
    run the risk of overwriting previous searches.  The name of the
    output file can be changed by clicking on "Change output filename"
    and entering a new string, e.g. "filename".  Data will be written
    to "filename".tmp during the search, and "filename".fit once the
    search has finished.

II.  Files in the model/ directory:




sample .m output files:


III. Files in the optmz/ directory

mulfit.hoc:  goes just above mulfit/ directory
feature_weaver.mod:  to incorporate new Vector functions

     simanneal_seq_weaver_Feb07.hoc  (Unconstrained SA)
     simanneal_cardoso.hoc           (Constrained SA + Recenter)

IV.  Disclaimer

I think this is everything a user would need to reproduce my
functions.  I removed a lot of comments & debugging stuff from the
e_apwinfrcv.hoc file - I hope I didn't break something in the

Other files in this directory:

weaver06_Optimization.pdf:  The Weaver & Wearne reference cited above.

simanneal_unconst.html: HTML help file written by Andrew Davison
(Unconstrained SA)

simannrctr_help.pdf:  Constrained Simulated Annealing help file.

20131216 Model updated to work with NEURON version 7.3.  A variable
"t" was changed to "tt" in the opmtx/feature_weaver.mod file.

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