Detection of NGF-b1 expression in the olfactory bulbs of rhesus macaques immunized by the intranasal route with the HIV-1 envelope peptide cocktail (pep-mix) using either the mucosal adjuvant mutant cholera toxin CT2* (the first three panels on the left-side indicated by monkey numbers, 53, 56, and H361) or native cholera toxin (nCT, right-side panel indicated by monkey number H341). Frozen tissue sections were subjected to anti-NGF-b1 antibody immunohistochemistry staining (upper panels) and immunofluoresence straining (lower panels) by reacting with avidin-biotin conjugate, followed by incubation with HRP-conjugated streptavidin or streptavidin-Alexa Fluor 488.