The proposed research will examine plasticity of responses in the dorsal cochlear nucleus (DCN), one of the first sites of integrative processing within the auditory system. The strengths of inputs from somatosensory brainstern nuclei into the DCN will be manipulated using variations of established protocols for inducing long-term synaptic changes in other brain regions, including but not limited to tetanic electrical stimulation of the input pathways. Input through the somatosensory pathways will be used to investigate whether plastic changes of sound-evoked responses can be induced in the DCN. Finally, the sites of plastic changes will be examined using pharmacological manipulations and stimulation at selected sites within the somatosensory-DCN pathway. This research will provide insight into the association between the somatosensory and auditory systems and into the overall function of the DCN. The work will contribute to the general understanding of the mechanisms and functional significance of plastic changes within the brain, which are relevant to normal development, to pathology (such as somatic tinnitus), and to recovery after damage.
