Grant: Discovery Grants Program - Individual

) The proposed research will examine the role of the central nervous system in auditory perception and the discrimination of temporal features of complex sounds. Neural circuits located along the auditory pathway from the ear to auditory cortex are important for the identification of complex sounds associated with environmental events or species-specific communication signals including human speech sounds. The ventral nucleus of the lateral lemniscus (VNLL) is a major collection of neurons in the auditory pathway that is thought to be involved in processing temporal properties of complex sounds. This research project will examine how the neurons in the VNLL contribute to the analysis of temporal features of sounds. We will record physiological responses from single neurons in the rat's VNLL while applying pharmacological agents to the cells to determine how their synaptic chemistry regulates auditory response characteristics. We will also examine the response properties of cells elsewhere in the auditory pathway while activity in the VNLL is blocked by either drug application or local damage of nerve cells. These studies will allow us to determine the functional contribution of the VNLL to central auditory processing. In addition, we will conduct behavioral studies to determine how damage to the VNLL affects hearing and the ability of animals to distinguish sounds based on their temporal structure. The studies will shed light on how complex features of sounds are processed by neural circuits and represented by neural activity within the central auditory system. The outcome of the experiments will also have important implications for understanding deafness and central auditory processing disorders in humans.