Additional file 2. Montage image showing a large section of porcine spleen stained for TH. TH + nerve fibers were more prevalent in the red pulp (rp) than the white pulp (wp), trabeculae (t), or capsule (c). Sympathetic nerve bundles (nb) are scattered throughout the section. Montage was created by stitching multiple 10X images using an Olympus BX41 microscope equipped with an Olympus DP74 digital camera and cellSens Dimension software.