Fig. 8.

Ageing promotes a 5% decrease of myonuclear density, while PPARβ agonist treatment restores a juvenile phenotype. a Quantification of nuclei number in isolated DAPI-stained fibres harvested from tibialis anterior of 10-week-old (Ct, Tg, GW) and 19-month-old (19Ct, 19Tg, 19GW) B6D2 mice (n = 160, four animals per group, 40 fibres per animal). Mice were either treated with vehicle only (Ct, 19Ct) or untreated PPARβ transgenic mice (Tg, 19Tg) or treated for 4 days with GW0742 (GW, 19GW). *p < 0.01, different from 10-week-old mice groups (Ct, Tg, GW); pound sign p < 0.05, different from vehicle-treated groups (Ct, 19Ct). b Distribution of myofibres population counted in a using the same classification as in Fig. 1b. Percentage of each group, mean number of nuclei in each group (Mean) and standard deviation (s.d.) are reported for each experimental condition