Recent animal work has suggested that cochlear synapses are more vulnerable than hair
cells in both noise-induced and age-related hearing loss. This synaptopathy is invisible in
conventional histopathological analysis, because cochlear nerve cell bodies in the spiral
ganglion survive for years, and synaptic analysis requires special immunostaining or serial-
section electron microscopy. Here, we show that the same quadruple-immunostaining
protocols that allow synaptic counts, hair cell counts, neuronal counts and differentiation of …