Changes in the Inner Gene Expression of Lateral Olivocochlear Receptors After the Loss of the Descending Cortical Pathway

Almost all experimental paradigms in which sound stimulation is involved assume the stability along time of central sensorineural processing. However, several recent studies demonstrate that brain cortex dynamically regulates the receptor analysis of sound. We are interested in how the descending cortical control regulates, in the long term, molecular markers of the inner ear function. It has been shown that the auditory cortex sends a long connection to medial olivocochlear neurons (MOC) located in the pons. These neurons dynamically regulate the amplification and gain control of the organ of Corti and the cochlear nerve. After sound stimulation MOC connections to the cochlea regulate OHC motility and in consequence the mechanism for transduction in the Organ of Corti. Recent behavioral studies have shown that cortical control modifies the response of the ear in sound localization and selective attention, raising the relevance of knowing more about the fundamentals of the feedback regulation of neural plasticity. In this paper, we analyze the effects of cortical deprivation on the expression of some relevant molecular markers of the inner ear related to the olivocochlear regulation in an attempt to understand the cellular basis for plastic descending regulation of hearing.