Fig. 2

GI dysfunction in presymptomatic αS Tg mice is present starting from 3 months of age. GI functionality was evaluated through behavioral tests in presymptomatic 3, 6, 9 and 12 (if healthy) months old αS Tg mice and nTg littermates. Behavioral analysis showed significant constipation in young and adult Tg animals and nTg age-matched littermates. Each trial was performed 1 to 3 times per animal on non-consecutive days. Groups comprised of 20–30 mice with similar presence of females and males. a The Whole Gut Transit Time (WGTT) is increased in presymptomatic αS Tg mice versus controls already at 3 months and exacerbates with age, reaching an average 3 h 12 min delay in Tg animals by 6 months of age. The GI transit time was recorded as the time for a non-absorbable dye to travel through the GI tract. b, c, d, e Presymptomatic αS Tg mice excreted a reduced number of stools but with an increased length already at 3 months of age compared to controls, although the pellets total weight remained unchanged. b Representative image of stools collected in 1 h trial from a 6 month old αS Tg mouse and littermate. Notably pellets from young Tg mice are longer but less abundant. c, d, e Total pellets were collected in 1 h trail. Stools from Tg mice were consistently longer and less abundant although their total amount remained unchanged. f Food intake was measured in a 24 h trial. No significant difference between groups until 9 months of age in the amount of chow was found. Values on graphs are expressed as raw data and are given as the mean ± SEM (n = 20–30 per group). * p < 0.05; ** p < 0.01; *** p < 0.001, **** p < 0.0001, two-way ANOVA followed by Fischer’s LSD test