Effect of PACAP38 on olfactory neurogenesis. PanelsA, B, Dual immunofluorescence localization is shown. Panel A, Primary olfactory cultures demonstrate colocalization of PAM and amidated PACAP38 to NST-positive cells (affinity-purified PHM antibody). Top, A cell double labeled for PAM (left) and NST (right) is shown.Bottom, A cell double labeled for PACAP (left) and NST (right) is shown.Panel B, PAM (top left) and amidated PACAP38 (bottom left) were also colocalized to GFAP-positive cells (right). Panel C, PACAP38 increases neuronal number. Primary olfactory cultures were incubated for 2 d with 10−10 to 10−8m PACAP38. The number of neurons (NST-positive cells) and glia (GFAP-positive cells) was counted. The experiment was replicated four times, and results were verified by an independent observer. VIP (10−8m) had no effect on the number of neurons or glia. PanelD, PACAP38 increases BrdU labeling of olfactory neurons. Primary olfactory cultures were incubated with BrdU and 10−8m PACAP38 for 2, 6, 18, and 24 hr. NST-positive cells were counted for BrdU-positive nuclei in control untreated wells (C) or PACAP38-treated wells (PAC). The total number of BrdU-positive cells is listed per 50 neurons counted. E, PACAP38 stimulates neuronal survival. Incubation of cells with PACAP38 for 2 d reduced the number of cells undergoing apoptosis by 42% as assayed by TUNEL labeling (**p < 0.001).nn, Number of neurons; pos, positive. Scale bars: panel A, 12.5 μm; panel B, 25 μm.
