Figure 2. Treatment with 27-residue pituitary adenylate cyclase-activating peptide (PACAP-27) enhanced neurite outgrowth in trigeminal nerve (TgN) cells. A: Cultured vehicle TgN cells were labeled with immunofluorescent antibody to neurofilament and treated with B: 10^-7 M nerve growth factor (NGF) or C: 10^-6 M PACAP. D: The graph shows percentage of TgN cells with elongated neurites when incubated with NGF, PACAP-27, or PACAP-27 plus inhibitor PACAP 6-27. Data are means±SEM (n=9). *p<0.05 is relative to vehicle for NGF and PACAP, or relative to PACAP for the PACAP plus PACAP antagonist group (Dunnett’s t test). E: The graph shows percentage of TgN cells with elongated neurites after stimulation with increasing dosages of PACAP-27 or control VIP. Data are means±SEM (n=3). *p<0.05 is relative to vehicle.