Luciferase activity in the brainstem (A) and in the tongue (B) 10 days after i.m. injection of Ad-PGK-luc in 45-day-old (D45) and 130-day-old (D130) mice. Solid and shaded bars, mutant SOD1 G93A mice (G93A) and control littermates (WT), respectively. Data are means ± SEM from three independent experiments; n = 14 at D45 and n = 11 at D130 in each group. Dark and light checked bars, normal SOD1 mice (NS, n = 3) and control littermates (WTNS, n = 4), respectively. (C and D) Numbers of X-Gal- (C) or TMB-positive (D) motoneurons in the hypoglossal nucleus after injection of Ad-RSV-βgal (C) or HRP (D) into the tongue of 130-day-old G93A (solid bars) and wt (shaded bars) mice. Data are means ± SEM for six (C) or seven (D) animals from two independent experiments. (E and F) Luciferase activity in the brainstem (E) and the tongue (F) 10 days after injection of Ad-PGK-luc into the tongue pretreated with BoNT (striped bars) or PBS (shaded bars). Data are means ± SEM for four animals. Luciferase activity is expressed in RLU/μg of protein (A and B; E and F). Values were compared by Student's t test (*, P < 0.05); **, P < 0.01; ***, P < 0.001.