"Blocking the small-conductance (SK) calcium-activated potassium channel promotes
burst firing in dopamine neurons both in vivo and in vitro.
...
We focus on the underlying plateau potential
oscillation generated in the presence of both apamin and TTX, so that
action potentials are not considered.
We find that although the plateau
potentials are mediated by a voltage-gated Ca2+ current, they do not
depend on the accumulation of cytosolic Ca2+, then use a computational
model to test the hypothesis that the slowly voltage-activated
ether-a-go-go–related gene (ERG) potassium current repolarizes the
plateaus.
The model, which includes a material balance on calcium,
is able to reproduce the time course of both membrane potential
and somatic calcium concentration, and can also mimic the induction
of plateau potentials by the calcium chelator BAPTA." See paper for more.
Reference:
1 .
Canavier CC, Oprisan SA, Callaway JC, Ji H, Shepard PD (2007) Computational model predicts a role for ERG current in repolarizing plateau potentials in dopamine neurons: implications for modulation of neuronal activity. J Neurophysiol 98:3006-22 [PubMed]
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