This is the readme for the model associated with the paper:

Rubin JE, Shevtsova NA, Ermentrout GB, Smith JC, Rybak IA (2009)
Multiple rhythmic states in a model of the respiratory central pattern
generator. J Neurophysiol 101:2146-65

This models runs under XPP available from 
http://www.math.pitt.edu/~bard/xpp/xpp.html

After downloading and extracting the archive the program can be
started for example under linux by cd'ing to the new folder and typing
xppaut rubinetal_resp_cpg.ode

Click on Initialconds -> Go

When complete click on Window/zoom -> (W)indow and then change "X Hi"
to 10000 and click OK.  Then you should see a graph like:



which is similar to the first trace in Figure 2A from the paper.