Computational bifurcation analysis to find dynamic transitions of the corticotroph model
Özet
The corticotroph model is a 7th order nonlinear differential equation
system derived for representing the action potential dynamics of corticotrophs; one
of the endocrine cells that are responsible for stress regulation. Here we use
numerical continuation methods to perform bifurcation analysis since controlling
bifurcations in the hormonal dynamics may bring some new insights in the
treatment of stress-related disorders. We study the bifurcation structure of the
system as a function of the BK-channel dynamic parameters and all maximal
conductances. We identify the regions of bistability and bifurcations that shape the
transitions between resting, bursting, and spiking behaviors, and which lead to the
appearance of bursting which is directly connected to stress regulation.
Furthermore, we find that there are two routes to bursting, one is the experimentally
observed BK-channel dynamics and the other is Ca2+ channel conductance only.
Finally, we discuss how some of the described bifurcations affect the dynamic behavior
and can be tested experimentally.