The models for the paper:

A phantom bursting mechanism for episodic bursting, R. Bertram, J. Rhoads and W.P. Cimbora, 2008, Bulletin of Mathematical Biology, 70, 1979-1993.

PubMed ID: 18648884

doi: 10.1007/s11538-008-9335-0

are available in xpp at the authors web site:

https://www.math.fsu.edu/~bertram/software/neuron/

After starting the BMB_08b.ode, and then for second graph BMB_08b_noisy.ode below in xpp select Initalconds -> Go to generate these images:

screenshot 1 screenshot 2

and the noise-less version is available at cellml.org:

https://models.cellml.org/exposure/48e767ee37f347e1a3876d0549a0866b/bertram_2008.cellml/view

After loading the bertram_2008.cellml.xml in opencor, right click the membrane voltage in the parameter panel and select to plot against either integration variable (top plot), or s2 (buried in Plot against -> ls2 -> s2 -> s2):

screenshot 3 It reproduces figure 4, where g_K1 = 20pS