Fig 2. CB₁ immunoreactivity of the Olfactory bulb.

CB₁ immunoreactivity of a six-month-old Beagle dog (A, B, C) and four-week-old dog (D). Strong immunoreactivity of the glomerular layer (GL), lack of immunoreactivity in the external plexiform layer (EPL) and mitral cell layer (ML), while moderate immunoreactivity of the internal plexiform layer (IPL) are observed in the six-month-old Beagle dog (A). Detailed immunoreactivity of the GL (arrow) is depicted in B. In the six-month-old Beagle dog, a population of cells within the internal granule cell layer (arrow) is strongly CB₁ receptor positive (C). Contrary, the glomerular layer in the four-week-old dog was only slightly CB₁ receptor positive (D). IHC was performed using the avidin-biotin-peroxidase complex (ABC) method.