We quantified expression using high resolution images collected using a Nikon Eclipse Ti2 (40x objective with or without additional 2x built in objective) or an Olympus IX83 under 40x or 63x magnification. For comparison between different regions, we scanned images using the same settings. To quantify cells expressing DRD1 and DRD2 in the caudate and putamen (Figure 4D), we chose ten representative areas from each striatal region (Figure 4C). We adjusted the threshold of the nuclei images and converted them to black and white using the “Make Binary” function in ImageJ.86 We then filled the holes using the “Fill Holes” function and separated overlapping nuclei with the “Watershed” function. We identified the number and regions for nuclei using the “Analyze Particles” function and added the nuclear contours to “ROI Manager”. We then opened the DRD1 and DRD2 images and identified the DRD1 and DRD2 grains using the “Find Maxima” function in ImageJ and then obtained binary images with a single pixel for each local maxima by choosing output type of “Single points”. We measured the integrated intensity of DRD1 and
