In order for us to interpret the outside world, neurons in the brain must detect and convey different aspects of sensory stimuli embedded within complex patterns of synaptic input. Sensitivity to these sensory features is conferred not only by the synaptic connectivity of neurons, but also from the properties of their dendrites, the tree-like structures along which synaptic activity propagates to the site of action potential generation in the axon. Dendrites contain diverse subtypes of voltage- and ligand-gated ion channels, which distort the amplitude and time course of synaptic activity. In this way, the dendrites actively regulate what aspects of sensory information are ultimately communicated to the neuron’s network targets.
The focus of my laboratory is to identify the cellular mechanisms by which dendrites transform the synaptic activity they receive into new patterns of action potential firing. We are examining this question in neurons of the mammalian central auditory system, where an understanding of synaptic integration in single cells bears directly on the broader question of how the brain detects different features of sound that in turn are critical for diverse processes such as speech perception and sound localization.
We use dendritic patch-pipette recordings and optical imaging techniques in living brain slices to study the distribution, biophysical properties, modulation and functional significance of ion channels in single neurons. In addition, imaging techniques and multiple simultaneous recordings of connected neurons are being used to examine how synaptic information is processed in auditory circuits.