Figure 5.

A simple two-stage model captures the major features of orthodromic driving. (A) Depiction of the modeling. The first stage is the conversion of light pulses into local activity in the RSC, which is modeled by convolving the step pulses of light with a step function scaled by a decay process. The second stage is the conversion of the upstream RSC activity into downstream M2 activity, which is modeled by convolving the RSC activity with an exponential process with a temporal lag. The models were fitted to the data over the 0-60 ms post-stimulus interval. See text for additional details. (B) The fitted RSC responses (red) were generated by modeling the light pulse→RSC transfer function as described in (A). The AAV9-CaMKII-hChR2-eYFP data traces (gray) are shown superimposed. (C) Plot of the residuals (black trace), calculated by subtracting the mean fitted traces (red) from the mean data traces (gray). (D) The fitted M2 responses (green) were generated by modeling the RSC→M2 transfer function as described in (A). The data traces (gray) are shown superimposed. (E) Plot of the residuals (black trace), calculated by subtracting the mean fitted traces (green) from the mean data traces (gray).