Existence and Control of Go/No-Go Decision Transition Threshold in the Striatum
Fig 9
Modulation of the DTT in the striatum.
(Left) Each contour encloses an area in the parameter space of input correlation (W) and input firing rates, in which the firing rate of D1 MSNs exceeds that of D2 MSNs. The blue contour represents the healthy state of the striatum. Loss of dopamine results in a decrease in the strength of excitatory inputs to the D1 MSNs and, therefore, the blue contour shrank to the red contour indicating that for a large range of firing rates and correlations D2 MSNs have higher firing rate than D1 MSNs. The green contour on the other hand depicts a state in which there is a high level of dopamine in the striatum (e.g. in PD patients on L-Dopa treatment) because excessive dopamine increases the overall excitability of D1 MSNs, thereby expanding the region in which D1 MSNs have a higher firing rate. We refer to the region in which the firing rates of D1 and D2 MSNs are comparable as a region of high-conflict. (Right) The blue contour is the same as in the left panel. The orange contour shows how the increase in shared correlation (B′) could increase the region of high-conflict (RHC).