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Table 1 Descriptions and values of the neuron–astrocyte mass model parameters

From: A Theoretical Study on the Role of Astrocytic Activity in Neuronal Hyperexcitability by a Novel Neuron-Glia Mass Model

Parameter

Interpretation

Value

Neuronal compartment

A

Average excitatory synaptic gain

\(3.25~\mbox{mV}\)

B

Average inhibitory synaptic gain

\(22~\mbox{mV}\)

\(\frac{1}{a}\)

Time constant of excitatory postsynaptic potentials

\(\frac{1}{100}~\mbox{s}\)

\(\frac{1}{b}\)

Time constant of inhibitory postsynaptic potentials

\(\frac{1}{50}~\mbox{s}\)

\(e_{0}\)

Half of the maximum discharge rate of a neuronal population

\(2.5~\mbox{s}^{-1}\)

\(v_{0}\)

Basic excitability threshold for neurons

\(6~\mbox{mV}\)

r

Stiffness of neuronal excitability

\(0.56~\mbox{mV}^{-1}\)

\(C_{1}\)

Strength of the synaptic connections from P to \(P'\)

135

\(C_{2}\)

Strength of the synaptic connections from \(P'\) to P

108

\(C_{3}\)

Strength of the synaptic connections from P to I

33.75

\(C_{4}\)

Strength of the synaptic connections from I to P

33.75

G

Gain of the direct excitatory feedback from P to itself

40

Glial compartment

W

Tunes the peak amplitude of glutamate concentrations

\(53.6~\mu\mbox{M}\cdot\mbox{s}^{-1}\)

Z

Tunes the peak amplitude of GABA concentrations

\(53.6~\mu\mbox{M}\cdot\mbox{s}^{-1}\)

\(w_{1}\)

Tune the rise and decay times of glutamate release transfer function

\(90~\mbox{s}^{-1}\)

\(w_{2}\)

\(33~\mbox{s}^{-1}\)

\(z_{1}\)

Tune the rise and decay times of GABA release transfer function

\(90~\mbox{s}^{-1}\)

\(z_{2}\)

\(33~\mbox{s}^{-1}\)

\(V_{G}^{{\mathrm{ne}}}\)

Maximal rate of glutamate uptake by neurons

\(0.5~\mu\mbox{M}\cdot\mbox{s}^{-1}\)

\(V_{G}^{{\mathrm{ae}}}\)

Maximal rate of glutamate uptake by astrocytes

\(4.5~\mu\mbox{M}\cdot\mbox{s}^{-1}\)

\(s_{g}\)

Activation threshold of sigmoid glutamate uptakes

\(6~\mu\mbox{M}\)

\(r_{g}\)

Stiffness of sigmoid glutamate uptakes

\(0.9~\mu\mbox{M}^{-1}\)

\(V_{\gamma}^{{\mathrm{ae}}}\)

Maximal rate of astrocyte GABA uptake

\(2~\mu\mbox{M}\cdot\mbox{s}^{-1}\)

\(K_{\gamma}^{{\mathrm{ae}}}\)

Maximal concentration for Hill dynamics of astrocyte GABA uptake

\(8~\mu\mbox{M}\)

\(V_{\gamma}^{{\mathrm{ne}}}\)

Maximal rate of neuronal GABA uptake

\(5~\mu\mbox{M}\cdot\mbox{s}^{-1}\)

\(K_{\gamma}^{{\mathrm{ne}}}\)

Maximal concentration for Hill dynamics of neuronal GABA uptake

\(24~\mu\mbox{M}\)

\(V_{G}^{c}\)

Rate of glutamate degradation by astrocytes

\(9~\mu\mbox{M}\cdot\mbox{s}^{-1}\)

\(V_{\gamma}^{c}\)

Rate of GABA degradation by astrocytes

\(9~\mu\mbox{M}\cdot\mbox{s}^{-1}\)

Neuron excitability modulations by neurotransmitter concentrations (feedbacks)

\(v_{G}\)

Excitability threshold of glutamate feedback function

\(30~\mu\mbox{M}\)

\(r_{G}\)

Stiffness of sigmoid glutamate feedback function induced by glutamate

\(0.15~\mu\mbox{M}^{-1}\)

\(m_{G}^{P}\)

Maximal coupling gain of glutamate feedback on pyramidal neurons

\(2.5~\mbox{mV}\)

\(m_{G}^{I}\)

Maximal coupling gain of glutamate feedback on interneurons

\(1~\mbox{mV}\)

\(v_{\gamma}\)

Excitability threshold of GABA feedback function

\(25~\mu\mbox{M}^{-1}\)

\(r_{\gamma}\)

Stiffness of sigmoid GABA feedback function

\(0.12~\mu\mbox{M}^{-1}\)

\(m_{\gamma}\)

Maximal coupling gain of GABA feedback

\(1~\mbox{mV}\)