Research Article

Parallel Excitatory and Inhibitory Neural Circuit Pathways Underlie Reward-Based Phasic Neural Responses

Table 2

Model parameters.

SymbolDescriptionValue

backgroundICBaseline of CS input0.30
backgroundIRBaseline of US input0.20
Exponentially decaying time constant of CS/US input20.0
The time constant of VS neurons36.0
The time constant of the change of weight 6
CS-to-VS weight learning rate13.0
Maximum CS-to-VS synaptic weight4.00
CS-to-VS weight decay rate13.00
The baseline activation level of DA neurons0.194
Phasic dopamine signal threshold0.001
Striosomal spectrum spacing16.5
Striosomal spectrum offset30.9
Calcium activation rate3.00
Calcium concentration maximum5.00
Calcium spike threshold0.37
Calcium passive decay rate12.00
Calcium recovery rate0.108
Activity-dependent calcium inactivation rate48.0
Calcium inactivation threshold0.18
Striosomal learning rate500.00
Striosomal output threshold0.27
Maximum CS input-to-striosomal synaptic weight20.0
CS input-to-striosomal synaptic weight decay rate40.0
The time constant of the change of 36.00
The time constant of the change of 6.00
VS-to-pre-PPTN synaptic weight1.00
The time constant of the change of 36.00
The time constant of the change of 6.00
VS-to-pre-VP synaptic weight1.00
The background input to the PPTN0.10
VS-to-PPTN input weight3.00
PPTN neurons response time constant36.00
The background input to the VP0.10
VS-to-VP input weight3.00
VP neurons response time constant36.00
The difference signal threshold of the excitatory and inhibitory effects previous to PPTN0.006
The difference signal threshold of the excitatory and inhibitory effects previous to VP0.006
GPb neuron response time constant36.00
The background input to the GPb0.60
VP-to-GPb synaptic weight1.00
Striosome-GPb synaptic weight0.35
LHb neuron response time constant36.00
The background input to the LHb0.10
GPb-to-LHb synaptic weight5.00
GPb output signal threshold0.45
RMTg neuron response time constant36.00
The background input to the RMTg0.10
LHb-to-RMTg synaptic weight2.00
LHb output signal threshold0.25
DA neuron response time constant36.00
The background input to 0.40
RMTg-to-VTA/SNc synaptic weight0.80
PPTN-to VTA/SNc synaptic weight1.00
PPTN output signal threshold0.10
Maximum hyperpolarization of DA neurons0.10