Dependence of the fidelity and accuracy of the neuronal transformation on its firing rate. Results shown for neurons from the GP (red), EP (blue) and SNr (green). (A) Precision of the neuronal responses to multiple injections (30–50) of the same input, as a function of the firing rate. The precision is defined as the mean widths of the events in the smoothed PSTH of each session. Solid lines represent the linear fitting function (GP: R2 = 0.02, p = 0.08, EP: R2 = 0.14, p < 0.05, SNr: R2 = 0.06, p < 0.05). (B) Reliability estimation of neuronal responses to repeated injections of the same noise, calculated as the fraction of spikes that occurred in PSTH events. Solid line represents the exponential fitting function (GP: R2 = 0.43, p < 0.001, EP: R2 = 0.78, p < 0.001, SNr: R2 = 0.66, p < 0.001). (C) Victor-Purpura distance (q = 0.15) as a function of the firing rate. Each dot represents the mean Victor-Purpura distance between all pairs of spike train trials recorded in a single session, as a function of the neuron firing rate in that session. The solid lines represent the linear fitting function in each of the nuclei (GP: R2 = 0.29, p < 0.001, EP: R2 = 0.47, p < 0.001, SNr: R2 = 0.14, p < 0.01).