COMPUTATIONAL BIFURCATION ANALYSIS TO FIND DYNAMIC TRANSITIONS OF THE CORTICOTROPH MODEL

Yıl 2018, Cilt: 60 Sayı: 1, 41 - 64, 31.07.2018

Sevgi Şengül Ayan , Ahmet Kurt

Öz

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 is 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 the 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 dynamic behavior and can
be tested experimentally. 

Anahtar Kelimeler

Dynamical System, Bifurcation analysis, Corticotroph Model, Bursting Oscillations, Spiking oscillations

Kaynakça

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