The auditory system, in particular the cochlear nucleus, is an excellent system to study how the brain performs complex computations. Acoustic information is initially represented in the auditory nerve, which encodes the frequency content of sounds reaching the ears. Subsequent processing steps necessary to extract functionally-relevant information from this primary representation of sound is initiated by computations performed by the neural circuitry of the cochlear nucleus. This system provides an excellent opportunity to investigate detailed mechanisms of synaptic plasticity, neuronal integration and network function in a well-defined circuit that can be preserved experimentally in slice preparations. Because the representation of sounds by the auditory nerve and many aspects of basic auditory circuitry are relatively well-described, the behavior and function of these neural circuits can be studied in a physiologically-relevant context. ? ? Our experimental approach combines electrophysiology and optical techniques to study synaptic transmission and plasticity in the cochlear nucleus and auditory brainstem. These studies contribute to our understanding of how sensory stimuli are represented by neuronal activity and will enable improvements in our understanding and treatment of hearing disorders. More generally, the auditory system provides an ideal system for linking mechanisms of synaptic plasticity and integration to functionally-relevant coding of neural information relevant for localization, identification and interpretation of sounds.? ? As a new investigator in NIDCD, starting in August 2007, I have been setting up equipment for electrophysiology and cellular imaging using in vitro and in vivo techniques. Two fellows are currently working in the lab and additional personnel are expected to join in 2009. We are performing preliminary experiments to record from neurons in the cochlear nucleus. Our goal is to investigate the role of synaptic plasticity in controlling the responses of different cell types in the cochlear nucleus, and specifically to characterize the mechanisms of endocannabinoids in modulating synaptic transmission in the dorsal cochlear nucleus. We are also developing custom software tools for combining electrophysiology data acquisition and CCD imaging.
