Table 3 

Model Kinetics and Rate Constant Values. 

Abbreviation 
Description 
Default Values 


k_{crh} 
Rate constant for generation of CRH 
3.8 × 10^{1} 
k_{acth} 
Rate constant for generation of ACTH 
1.085 × 10^{1} 
k_{cor} 
Rate constant for generation of cortisol 
2.4 × 10^{3} 
k_{cdeg} 
Rate constant for the degradation of cortisol. 
8.5 × 10^{3} 
V_{crh} 
Saturation level of inhibition for hypothalamic cells 
1 
V_{acth} 
Saturation level of inhibition for pituitary secretory cells 
1 
k_{da} 
Dissociation constant for cortisol in the hypothalamus 
50 
k_{dc} 
Dissociation constant for cortisol in the pituitary 
50 
k_{gr} 
Concentration of cortisol at which GR receptors are 50% saturated. 
1 × 10^{8} 
k_{mr} 
Concentration of cortisol at which MR is 50% of its max 
2.5 × 10^{3} 
k_{mad} 
Rate constant for the deactivation of MR receptors 
1 
k_{non} 
Rate constant for the inhibition of CA1 neurons by MR receptors. 
4.99 × 10^{2} 
k_{GRD} 
Rate constant for degradation of GR activity 
4.45 × 10^{1} 
k_{ngf} 
Rate constant for stimulation of CA1 neurons by growth factors. 
10 × 10^{8} 
k_{nps} 
Rate constant for death of neurons. 
4.5 × 10^{2} 
k_{ngfs} 
Rate constant for neuronal growth factor decline. 
1 
k_{nbd} 
Rate constant for stimulation of NBD 
5 × 10^{2} 
k_{ses} 
Rate constant for stimulation of synaptic excitatory signals. 
1.049 
k_{sf} 
Rate constant for stimulation of synaptic firing 
1.049 
k_{so} 
Rate constant for stimulation of synaptic output. 
1.049 
k_{ho} 
Rate constant for stimulation of hippocampal output. 
1.049 
k_{hos} 
Rate constant for degradation of synaptic output 
5.5 × 10^{4} 
k_{SI} 
Rate constant for inhibition of synaptic firing by synaptic inhibitory signals. 
2.2 × 10^{1} 
k_{SGR} 
Rate constant for production of synaptic inhibitory signals. 
4.45 × 10^{1} 
k_{sos} 
Rate constant for stimulation of synaptic firing. 
1.049 
k_{sisd} 
Rate constant for decline in synaptic inhibitory signals 
3.8 × 10^{1} 
V_{crh} 
Saturation level of inhibition for hypothalamic cells 
1 
V_{acth} 
Saturation level of inhibition for pituitary cells 
1 
Vmax_{MRA} 
Maximum rate of activity of MR receptors 
1 × 10^{2} 
Vmax_{GRA} 
Maximum rate of activity of GR receptors 
1 × 10^{2} 
Ngr 
Hill coefficient for GR receptor Activity 
3.6 
Nmr 
Hill coefficient for MR receptor activity 
5.8 
HV 
Volume of Hippocampus 
100 


This table describes the rate constant expressions used to define the interaction between variables within the model. Rate constants were extrapolated and simplified from known biophysical and biochemical reactions within hippocampal and HPA tissues. MichalelisMenton steady state enzyme substrate reactions and the Hill receptorligand binding equations were used to define interactions between model variables. 

McAuley et al. BMC Neuroscience 2009 10:26 doi:10.1186/147122021026 