[Stimulation-dependent gene expression in the central auditory system]

Abstract

Acoustic or electrical stimulation activate specific populations of neurons in specific regions of the central auditory system to prepare for a molecular, structural, and functional remodeling within hours. Among the indicators for the initiation of neuronal remodeling is the expression of immediate early genes (IEGs). The IEG c-fos is one of the first genes to be expressed following sensory-evoked neuronal activity. In order to investigate activity-dependent neuroplasticity in the central auditory system we applied acute unilateral electrical intracochlear stimulation (EIS) in a rat model. By using different stimulation parameters we found that laterality, intensity, and frequency effect different kinds of neurons in different regions. We investigated the ventral and dorsal cochlear nucleus (VCN and DCN), the lateral superior olive (LSO), the central inferior colliculus (CIC), and the medial geniculate body (MGB). In each region a unique dynamic pattern of c-Fos expression was found.