FIG. 6.

Proximity analysis for ANF terminals and synaptic ribbons suggests that ribbon counts underestimate the synaptic degeneration in noise-exposed ears. A Group means (± SEMs) from ribbon analysis in the 22- and 32-kHz regions show that roughly twice as many ribbons from noise-exposed ears are not closely apposed by ANF terminals. Data based on 1,323 ribbons from control ears and 2,432 ribbons from noise-exposed ears. B, C Representative “thumbnail” images on which the analysis in A was based. Each thumbnail shows the x–y projection of the voxel space within 1 μm of a ribbon. Ribbons without associated ANF terminals are shown at the right: B9,10 and C8,9,10.