The Maturation and Aging of the Vertebrae of Marmosets

This study deals with the growth, maturation, and age changes to the cartilaginous end-plates of vertebrae from marmosets (Callithrix jacchus) varying in age from birth to 10 years. The cartilaginous end-plate is divided into an inner growth layer and an outer articular zone that abuts against the intervertebral disc. The growth cartilage gradually narrows and disappears by 1 year of age, when the animal reaches physical maturity. The articular cartilage undergoes changes in collagen and ground substance that leads to its calcification. There was a progressive resorption of the calcified articular cartilage beginning at 3 years of age and continuing throughout the aging period. In the vertebrae of 8- and 10-year-old animals, only a thin layer of calcified cartilage separates the disc from the underlying bone.