Model of corticotroph electrical activity

Two XPP files, described below, were used to generate figure panels described in:

“Modeling the diversity of spontaneous and agonist-induced electrical activity in anterior pituitary corticotrophs” Patrick Allen Fletcher, Hana Zemkova, Stanko S. Stojilkovic, Arthur Sherman Journal of Neurophysiology, Published 22 February 2017, Vol. no. , DOI: 10.1152/jn.00948.2016

The ODE files below can be downloaded and run using Bard Ermentrout’s XPPAUT simulation tool

JNP17.ode

This file describes corticotroph electrical activity without ER calcium dynamics, used to simulate spontaneous electrical activity and modulation by CRH-receptor activation

Notes:

• Ensure that the system is at steady state before running a dynamic pulse simulation. The initial condition is set to the hyperpolarized state used for Fig. 4B
• Set parameters as indicated below to obtain the trajectory of interest from Figures 3-6. Default model parameters produce low-frequency spiking
• To see the pulse profile, plot the auxiliary variable “g”

Figure 3B

• top (diamond) - gnab=0.22, gbk=1.1
• middle (circle) - gnab=0.22, gbk=0.25
• bottom (square) - gnab=0.22, gbk=0.05

Figure 4B

• top (diamond) - gnab=0.05, gcrhpulse=0.22, gbk=0.89
• middle (circle) - gnab=0.05, gcrhpulse=0.22, gbk=0.25
• bottom (square) - gnab=0.05, gcrhpulse=0.22, gbk=0

Figure 4D

• top (diamond) - gkir=3.5, kp=0.3, gkirpulse=-2.4, gbk=0.96
• middle (circle) - gkir=3.5, kp=0.3, gkirpulse=-2.4, gbk=0.25
• bottom (square) - gkir=3.5, kp=0.3, gkirpulse=-2.4, gbk=0

Figure 4F

• top (diamond) - gkleak=1.9, kp=0.1, gkirpulse=-1.875, gbk=0.96
• middle (circle) - gkleak=1.9, kp=0.1, gkirpulse=-1.875, gbk=0.5
• bottom (square) - gkleak=1.9, kp=0.1, gkirpulse=-1.875, gbk=0

Figure 6B

• top (diamond) - vmca=-8, CRHvmca=-6, gbk=0.98
• middle (circle) - vmca=-8, CRHvmca=-6, gbk=0.7
• bottom (square) - vmca=-8, CRHvmca=-6, gbk=0.1

Figure 7B

• top (diamond) - gcrh=0.105, kcabk=2, CRHkcabk=1.4, gbk=1
• middle (circle) - gcrh=0.105, kcabk=2, CRHkcabk=1.4, gbk=0.5
• bottom (square) - gcrh=0.105, kcabk=2, CRHkcabk=1.4, gbk=0.1

Figure 7D

• diamond - gcrh=0.105, kcabk=2, gbk=0.5
• circle - gcrh=0.105, kcabk=3.5, gbk=0.5
• star - gcrh=0.105, kcabk=3.5, gbk=0.05
• square - gcrh=0.105, kcabk=2, gbk=0.95

JNP17er.ode

This file describes the model of corticotroph electrical activity modified to include ER calcium dynamics and IP3 receptor dynamics, used for simulation of Gq-coupled AVP receptor activation

Notes:

• The initial condition is set to the hyperpolarized state used for Fig. 7B top
• Set parameters to following to obtain the trajectory of interest from Figure 8
• To see the pulse profiles, plot the auxiliary variable “g1” or “g2”

Figure 8B

• top (diamond) - gnab=0.14, gbk=1, gavppulse=0.07, prelavp=0.01
• middle (circle) - gnab=0.18, gbk=0.85, gavppulse=0.055, prelavp=0.0025
• bottom (square) - gnab=0.17, gbk=0.35, gavppulse=0.04, prelavp=0.001