*4.9. Image Analysis*

Images were obtained by an Axioskop fluorescence microscope (Carl Zeiss GmbH, Hamburg, Germany). Images were captured from six region-matched sections for nigral and striatal regions for each animal and converted into a gray scale with an 8-bit format using the ImageJ software version 1.48 (National Institute of Health, Bethesda, MD, USA). A threshold optical density was determined for each staining. Areas occupied by positive staining were quantified in thresholded images, normalized to the total area of interest region and calculated as percentage of total area.
