NEURON mod files from the paper:

Nicolas Maurice, Jeff Mercer, C. Savio Chan, Salvador Hernandez-Lopez,
Joshua Held, Tatiana Tkatch, and D. James Surmeier D2 Dopamine
Receptor-Mediated Modulation of Voltage-Dependent Na+ Channels Reduces
Autonomous Activity in Striatal Cholinergic Interneurons, J
Neurosci. 2004 Nov 17;24(46):10289-301.

This is the model demonstrated in Figure 10.G:

Figure 10. Modest reduction of Na+ channel currents mimics D2 receptor
effects on pacemaking...G, In a simulation of pacemaking (Na+ channel
density of 1.4 mS/cm2), mimicking the D2 receptor modulation by
selectively increasing Na+ channel entry into a slow-inactivated state
(as in D, E) slowed the discharge rate by >40%. Restoration of the
control values for this rate constant restored the discharge rate.

Sample model usage:

To mimic the modulation of the D2 receptor, use the "Set Value 1" and
"Set Value 2" buttons in the Change Variable Value panel.  This should
show the decrease in discharge rate seen in Figure 10.G.

Questions on how to use this model can be directed to Josh Held,
j-held@northwestern.edu