The gerbil cochlear nucleus is subject to a spongiform degeneration, the progression of which is dependent on auditory functional activity. The most affected region is the ventrolateral aspect of the caudal posterior ventral cochlear nucleus (PVCN). Lesion density and glial changes were quantified in this region for two age groups. Spongiform lesions increased significantly in area density from 4% in 60-day-old gerbils to 14% in 6-month-old gerbils. In spite of this significant increase in tissue damage, no gliosis was found. A significant age-related decrease in oligodendrocyte density was found in the PVCN.