This package contains the XPP scripts used to make the figures in
Maex R, Grinevich VP, Grinevich V, Budygin E, Bencherif M, Gutkin B (2014)
Understanding the role a7 nicotinic receptors play in dopamine efflux
in nucleus accumbens. ACS Chemical Neuroscience 5, 1032-1040.
More particularly, there are separate scripts for Figures 2B, 3B and 6, and
for the panels of supplementary Figures S4 and S5.
(Other figures did plot experimental data, or steady-state functions
which can easily be recovered from the scripts.
Some traces of other figures can also be recovered, for instance
the traces of Fig. 4B,C are also covered in Fig. S4C.)
The above paper presents voltammetric recordings of dopamine responses,
along with a minimal model explaining the nicotinic control of
dopamine efflux in nucleus accumbens.
This minimal model, implemented in XPP, was built to tell apart response components
generated by circuit mechanisms from response characteristics caused by
activation or desensitization of the receptors embedded in the circuit.
In brief, the model consists of two neuron types (GABA and dopamine producing)
and two nicotinic receptor subtypes (a7 and a4b2).
The two populations are just implemented as leaky integrators, the
receptor subtypes as two-gate (activation and desensitization) channels.
The two receptor subtypes have very different concentration- and time-dependencies.
By varying their relative expression on GABA versus dopamine producing neurons,
qualitatively strongly different responses can be generated.
The scripts are based on a previous model described in greater detail in
Graupner M, Maex R, Gutkin B (2013)
Endogenous cholinergic inputs and local circuit mechanisms govern
the phasic mesolimbic dopamine response to nicotine.
PLoS Comput Biol. 2013;9(8):e1003183. doi: 10.1371/journal.pcbi.1003183.