A: Low magnification image showing GFP-ir (green), CB and CR immunoreactivity (CB-ir and CR-ir, red and blue, respectively) in various layers of the OB. Most of the CB or CR immuoreactive interneurons are located in the GL. Some are found in the EPL. B, C and D: Enlarged images showing single labeling of GFP-ir, CB-ir and CR-ir, respectively, from the box region in the GL in panel A. E and F: High magnification images from the GL showing GFP-ir, CB-ir and CR-ir cells in OB sections either countralateral (B) or ipsilateral (C) to the olfactory peduncle lesion. CR and CB are expressed in two separate populations of interneurons. None of the GFP-ir interneurons are immunoreactive for CR. Most GFP-ir cells in the GL also express CB, while a few did not label with the CB antibody (pointed by arrows in B and C). PG cells that are positive for CB only are pointed by arrowheads. Scale: A, E and F, 20μm. B, C and D, 10μm.