Histologic analysis of cross sectional images of the ascending aorta in WT and mLMNA+mice. In this series of hematoxylin and eosin stained slides, changes are observed in the ascending aorta in wild type (WT) (A-C) and mLMNA+(D-F) mice during aging. Prominent thickening of the media occurs in the posterior wall (P) of WT mice but the media remains intact with a complete layer of smooth muscle cells (SMCs). In contrast, progressing at 12 months (F), the thickened media in the posterior wall of mLMNA+ mice becomes largely depleted of SMCs and extensive extracellular matrix is deposited. These damaged areas are bounded by a prominent adventitia that consists of fibroblasts, a dense layer of collagen and calcification at the boundary of media and adventitia (arrow) (m = months). Scale bar: 250 μm.