The Structure and Function of Cells in the Mammalian Cochlear Nucleus   The inset displays a sagittal view of a cat brain.  The location of the cochlear nucleus is shown by the structure in color.  The cerebellum normally blocks our view of the cochlear nucleusso it  has been removed in the black and white photograph.  AN: auditory nerve; DCN: dorsal cochlear nucleus; VCN: ventral cochlear nucleus; VN: vestibular nerve.

My research goal is to understand how sounds are analyzed and coded in the cochlear nucleus (CN).  All information about sound is represented by patterns of electrical activity in the auditory nerve.  Auditory nerve fibers convey this information to the brain by forming synapses with neurons in the CN.  Unlike the auditory nerve, the CN contains many different kinds of neurons that respond to sound in their own unique way.  Thus, it is a key site to study how sounds are translated into neural codes. This diversity is organized such that CN cells can be partitioned into distinct groups.  Members of a group share features (e.g.  morphology, inputs, cellular mechanisms, axonal targets) that  cause them to respond to sound in similar ways and to distribute their messages to common targets in the brain.  Our working hypothesis is that each group plays a specific role in the hearing pathway.  We seek to define these groups and understand their roles.  We use pathway tracing and immunocytochemical techniques to describe the morphology and neurochemistry of CN cells (Fig. 1).    We employ an in vitro preparation of the entire brain to make intracellular recordings from CN cells and subsequently fill them with a tracer to link structure and function (Fig. 2).  Ultimately, this knowledge should allow us to interpret structural anomalies resulting from deafness or noise-induced damage in terms of their effect on acoustic processing.