Aging in the rat medial nucleus of the trapezoid body. III. Alterations in capillaries

The medial nucleus of the trapezoid body (MTB), a large cell group in the rat brainstem auditory pathway, undergoes significant cell loss and loss of synapses with advancing age [5,6]. The purpose of the present study was to examine the microvasculature of the MTB in rats of the following ages: 3 months (MO), 6 MO, 24 MO, 27 MO, and 33 MO. In rats aged 24 to 33 MO, the following ultrastructural changes were observed in MTB capillaries: (1) large cavitations or spaces within capillary basal laminae, and (2) membranous debris, indicative of cellular degeneration within leaflets of capillary basal lamina. The volume density ratio (VDR) of capillaries decreases significantly between 6 and 33 MO of age.