Our aim is to understand the rules and mechanisms by which immature auditory circuits are refined during early life. During an early developmental period, the interplay of environmental and genetic factors establishes the neural circuits that underlie auditory perception in the adult brain. Current work in the laboratory focuses on the superior olivary complex (SOC) of auditory brainstem, and in particular on the lateral superior olive (or LSO).
We (mammals, reptilians, and even insects) use differences in sound intensity and timing between the two ears to localize sound sources along the aziumuth, and it is the SOC that computes these interaural intensity differences and interaural phase differences. Sound localization and binaural detection of signal in noise depend on the precise tonotopic (frequency-based) alignment of inputs to nuclei of the SOC, including the LSO. In the adult LSO, large bipolar neurons integrate excitatory (glutamatergic) inputs from the ipsilateral ear and inhibitory (glycine- and GABA-ergic) inputs from the contralateral ear to compute interaural intensity differences. One task of the developing brain, then, is to establish an adult LSO that is wired such that individual neurons receive inhibitory and excitatory inputs that respond to the same sound frequency. Major conceptual questions in the lab include general mechanisms of plasticity and development in inhibitory neural circuits and the manner in which specific patterns of neural activity may guide plasticity. Laboratory personnel use physiological (in vitro intracellular and in vivo extracellular electrophysiology), anatomical, and behavioral approaches to investigate the formation of these auditory circuits. |
