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Performance Limitations of Relay Neurons

Figure 10

Thalamocortical loop in motor signal processing.

(A) Simplified view of basal ganglia thalamo-cortical motor signal processing. Sensorimotor cortex generates the driving input and projects to the motor thalamus. The thalamus relay of cortical input is modulated by the basal ganglia (BG). (B) Relay reliability curves computed from our analysis as a function of and from (49). (C) Simulations of (basal ganglia output) from the computational study [15] for the Healthy, PD and PD with high frequency deep brain stimulation (HFDBS) cases. As we can see in the healthy case, the amplitude of the BG output, , is smaller compared to the PD BG output, resulting in a higher relay reliability. HFDBS increases the frequency, , of the BG output, resulting in a higher relay reliability. (D) Intuition of how reliability changes in the three cases. In PD, is larger, therefore, the diameter of the orbit tube is larger compared to the orbit tube for healthy. This results in more time spent in the unsuccessful response region , which leads to poor reliability. In contrast, in PD case with HFDBS applied, is larger and the gains decrease, which generates a smaller orbit tube. In this case, the state spends more time in the successful response region of the orbit tube, resulting in high reliability.

doi: https://doi.org/10.1371/journal.pcbi.1002626.g010