How to solve the calcium summation problem?
Posted: Mon May 16, 2016 4:00 am
When using the detailed calcium handling mechanism including the buffering and diffusion, I met a problem to simulate the repetitive firing of the soma in Purkinje cell. Let's take the example of cdp model in the NEURON BOOK, there will be a long tail part for the decay of the calcium transient. For repetitive firing of the Purkinje cell, if there is a long tail part for the calcium transient, then there will be buildup (or summation) of the resting calcium and finally both the resting and peak calcium concentration will shift as time goes by. Of course this may not be true in reality. I tried to increase the pump density in the cdp model to shorten the tail part and make the calcium concentration reach the resting level (a fixed value) quickly under spontaneously firing condition (about 50 Hz). However, under current injection, the firing rate can reach about 200 Hz. I can't increase the pump density further, because increase the the pump density to some range will reduce the peak amplitude of calcium transient significantly which will affect the calcium sensed by BK current.
Does anyone know some other effective methods to eliminate the summation effect of the calcium during fast firing? Thanks.
Does anyone know some other effective methods to eliminate the summation effect of the calcium during fast firing? Thanks.