There's lots of ways to capture a sequence of screen images into
an animated gif.  My favorite is Gif-gIf-giF from Pedagoguery
Software
   http://www.peda.com/
It's extremely convenient.  Runs under MSWin, not sure about OS X.

I understand that animated gifs can also be created with gimp,
which runs on lots of different platforms.

UNIX/Linux/OS X users have many other choices.  For example,
Alain Destexhe has made mpeg movies from NEURON simulations--
see

http://cns.iaf.cnrs-gif.fr/alain_demos.html

If you don't find a description of what he did, contact Alain,
who will be happy to provide it.

One way to capture a sequence of images is to modify NEURON's
run time system so that, every time the graphs are updated,
you automatically capture a new frame.  This procedure

proc steprun() {
   step()
   flushPlot()
   system(statement)
}

will execute statement after every update of the graphs.
statement of course could be a command that executes some other
program that captures a frame and saves it to a file.

Make a new file called initmovie.hoc that contains these
statements:

load_file("nrngui.hoc")
load_file("yoursessionfile.ses") // if you used the gui
                                  // to set up your model
   // otherwise do
   // load_file("yourhocfile.hoc")

proc steprun() {
   step()
   flushPlot()
   system(statement)
}

Then use NEURON to execute init.hoc and you're ready to go.

--Ted
