Photo of Dr. Burger

BurgerLab

R. Michael Burger Ph.D.

Auditory Neurobiology Research Lab

(Image: hair cells of the chick inner ear)

Our Research

I am interested in how the brain processes information about its sensory environment. The auditory system can process sound information with amazing precision. For example, auditory neurons can detect the tiny microsecond differences in arrival time of a sound between the two ears, a property that is related to a sound's location. The processing of acoustic cues is critical for all animals in a wide range of behaviors including predator-prey interactions and social communication. An elegant and elaborate neural circuitry has evolved in species across the animal kingdom to process this information.

My research centers on the question of how cellular, synaptic, and systems level properties are integrated to allow sensory neurons to extract and represent features of the acoustic environment. The vertebrate auditory system is composed of a rich network of brain regions that process sound signals over interconnected neural pathways. In general, each brain center is devoted to the computation of specific properties of sounds and these properties are encoded by virtue of the synaptic connections and intrinsic properties of neurons in the network. Find out more about our current projects here.

The Latest News

THE BALANCE OF SOUND

BIOLOGY

By Robert Nichols

GETTING VOCAL

A biological sciences graduate student leads and exploration of damselfish vocalizations

By Geoff Gehman ’89 M.A.

Photo of Rep. Susan Wild and Dr. Burger discussing research findings.

U.S. Congresswoman Susan Wild Visits Iacocca Hall Labs


Inhibitory Function in Auditory ProcessingThere seems little doubt that from the earliest evolutionary beginnings, inhibition has been a fundamental feature of neuronal circuits. - even the simplest life forms sense and interact with their environment, orienting or approaching positive stimuli while avoiding aversive stimuli. This requires internal signals that both drive and suppress behavior. Traditional descriptions of inhibition sometimes limit its role to the prevention of action potential generation which fails to capture the vast breadth of inhibitory function now known to exist in neural circuits. 

A modern view of inhibitory signaling comprises a multitude of mechanisms; For example, inhibition can act via a shunting mechanism to speed the membrane time constant and reduce synaptic integration time. It can act via G-protein coupled receptors to initiate second messenger cascades that influence synaptic strength. Inhibition contributes to rhythm generation and can even activate ion channels that mediate inward currents to drive action potential generation. Inhibition also appears to play a role in shaping the properties of neural circuitry over longer time scales. Experience-dependent synaptic plasticity in developing and mature neural circuits underlies behavioral memory and has been intensively studied over the past decade. At excitatory synapses, adjustments of synaptic efficacy are regulated predominantly by changes in the number and function of postsynaptic glutamate receptors. There is, however, inc...