"Midbrain dopamine neurons exhibit a novel type of bursting that we call “inverted square wave bursting” when exposed to Ca2+-activated small conductance (SK) K+ channel blockers in vitro. This type of bursting has three phases: hyperpolarized silence, spiking, and depolarization block. We find that two slow variables are required for this type of bursting, and we show that the three-dimensional bifurcation diagram for inverted square wave bursting is a folded surface with upper (depolarized) and lower (hyperpolarized) branches. ..."
Model Type: Neuron or other electrically excitable cell
Cell Type(s): Substantia nigra pars compacta DA cell
Currents: I Na,t; I L high threshold; I K; I h; I K,Ca
Genes: HERG KCNH2
Model Concept(s): Bursting; Calcium dynamics
Simulation Environment: MATLAB
Yu N, Canavier CC. (2015). A Mathematical Model of a Midbrain Dopamine Neuron Identifies Two Slow Variables Likely Responsible for Bursts Evoked by SK Channel Antagonists and Terminated by Depolarization Block. Journal of mathematical neuroscience. 5 [PubMed]