Peripheral Cell Loss Related to Calcium Binding Protein Immunocytochemistry in the Dorsal Cochlear Nucleus in CBA/CaJ Mice during Aging

Abstract

The influence of cochlear hair cell and spiral ganglia neuron loss on calcium binding protein immunoreactivity (calretinin, parvalbumin and calbindin) in the dorsal and posteroventral cochlear nuclei (DCN and PVCN) in CBA/CaJ (CBA) mice during aging (1–39 months) was determined. Since calcium binding proteins have buffering properties against calcium overload, they may have a protective role during aging. It is shown that the percentage of calretinin- and parvalbumin-immunopositive neurons in the DCN showed a statistically significant positive correlation with inner hair cell loss, outer hair cell loss, and spiral ganglion cell loss. A correlation was also found between aging and the auditory periphery, and calcium binding proteins in the DCN. These findings imply that the pathophysiological state of the auditory periphery may influence the neuronal homeostasis in the dorsal cochlear nucleus.

Cellular regulatory mechanisms influencing

“…In genetically deaf mice the age-dependent deterioration and the consequently decreased activity of the cochlear hair cells and spiral ganglion neurones were accompanied by a moderate increase in the number of parvalbumin positive cells in the CN. Interestingly, in the same time calbindin positivity slightly decreased in the DCN and remained unchanged in the VCN, while calretinin positivity was not modified in either the DCN or the VCN (54,55). The protective role of the Ca 2+ binding proteins was further emphasized by those experiments in which healthy mice were subjected to strong sound stimuli (53).…”

Hearing impairments, presbycusis and the possible therapeutic interventions

“…In the cochlea histological changes occur due to the progression of hearing impairment. In C57BL/6J, the degeneration of the abaxial cochlea neurons have association with the degeneration of peripheral hair cells as both leads to presbycusis (Idrizbegovic et al, 2001). In C57 mice in addition to early presbycusis, in the nucleus of ventral cochlea changes in sensitivity were also observed, as for the analysis of sound features like temporal cue, frequency and sound intensity in the central hearing system, the cochlear nucleus is responsible (Caspary et al, 2008).…”