Feedback of calcium signaling through calcium-activated potassium channels of a dendritic spine is investigated. To simulate such ion channels and the resulting spatial distribution of concentration, current, and membrane voltage within the dendritic spine , we applythe immersed boundary method with electrodiffusion . In this simulation method , the permeability to ion flow across the membrane is regulated by the amplitude of chemical potential barriers along the membrane . With spatially localized ion channels, chemical potential barriers are locally and stochastically regulated. This  represents the ion channel gating with multiple subunits, the open and closed states of which are governed by a continuous-time Markov process. The model simulation recapitulates an inhibitory action on voltage-sensitive calcium channels by  calcium-activated potassium channels in a stochastic manner with non-local feedback loop. The model also predicts higher calcium influx with more closely placed channel complexes, resolving a potential mechanism of differential calcium handling by \emph{locality of channel distribution . This work provides a foundation for future computer simulation studies of dendritic spine motility and structural plasticity.
We investigate calcium signaling feedback through calcium-activated potassium channels of a dendritic spine by applying the immersed boundary method with electrodiffusion. We simulate the stochastic gating of such ion channels and the resulting spatial distribution of concentration, current, and membrane voltage within the dendritic spine . In this simulation , the permeability to ionic flow across the membrane is regulated by the amplitude of chemical potential barriers . With spatially localized ion channels, chemical potential barriers are locally and stochastically regulated. This regulation represents the ion channel gating with multiple subunits, the open and closed states governed by a continuous-time Markov process. The model simulation recapitulates an inhibitory action on voltage-sensitive calcium channels by the calcium-activated potassium channels in a stochastic manner as a non-local feedback loop. The model predicts amplified calcium influx with more closely placed channel complexes, proposing a potential mechanism of differential calcium handling by \emph{ channel distributions . This work provides a foundation for future computer simulation studies of dendritic spine motility and structural plasticity.
R
Feedback of calcium signaling
We investigate calcium signaling feedback
R
is investigated. To simulate
by applying the immersed boundary method with electrodiffusion. We simulate the stochastic gating of
D
, we apply
D
the immersed boundary method with electrodiffusion
D
method
R
ion
ionic
D
along the membrane
A
regulation
D
of which are
A
the
R
with
as a
R
also predicts higher
predicts amplified
R
resolving
proposing
D
locality
R
of channel distribution
channel distributions