Figure 4. Cross sections of the gastrocnemius of 20-months old (A) WT and (B) DN-p38αAF/+ mice. The cross sections suggest that the age-associated decrease of the diameter of the WT gastrocnemius is delayed in DN-p38αAF/+ mice. (A) shows a cross section of the gastrocnemius of aged WT (20 mos) mice; (B) shows a cross section of the gastrocnemius of aged DN-p38αAF/+ (20 mos) mice. (GM), gastrocnemius; (PL), plantaris. (A) anterior; (P) posterior; (M) medial; (L) lateral. (C, D) Maximal cross-sectional area of the gastrocnemius of young (2 mos), middle aged (13.5 mos) and aged (20 mos) mice. (D) A bar graph presentation of the data in (B).