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Table 1 Symbols used in the model.

From: Model-based parametric study of frontostriatal abnormalities in schizophrenia patients

a Coefficient that represents the presynaptic suppression of DA release by the D2 autoreceptor
b Coefficient that represents the presynaptic depression of the frontostriatal glutamatergic neurotransmission by D2 receptor activation
B max relative D2 receptor density
BP AMPT Binding potential of the D2 receptor after DA depletion
[DA] Extracellular concentration of endogenous DA
[DA] AMPT Extracellular concentration of endogenous DA after depletion
F Free synaptic concentration of the administered antipsychotic drug
f (x) Activation function: f (x) = tanh (x), x ≥ 0
K APD Dissociation constant of the D2 receptor for the administered antipsychotic drug
K d Dissociation constant of the D2 receptor for the radiotracer
K DA Dissociation constant of the D2 receptors for endogenous DA
P D2 receptor occupancy by endogenous DA
P APD D2 receptor occupancy by the administered antipsychotic drug
P DA(APD) D2 receptor occupancy by endogenous DA competing with the administered antipsychotic drug
τ d Time constant of the DA neurons
τ s Time constant of the striatal neurons
τ y Time constant of DA release
V ps Normalized connectivity coefficient of the frontostriatal projection
W dy Coefficient representing DA releasability
W ps Connectivity coefficient of the frontostriatal projection
W sd Connectivity coefficient of the projection from the striatum to the DA nuclei
x d Population activity of the midbrain DA nuclei
x p Population activity of the PFC
x s Population activity of the striatum
y DA release in the striatum: y = [DA]