Research Areas and Techniques
How does an animal perceive a sensory stimulus? To address this question, our research focuses on the neural basis of olfactory perception and how context and experience influence it. Experiments involve both behavior and electrophysiology and concentrate on the rodent (rat and mouse) olfactory and limbic systems. New work investigates how humans perceive and process scents.
Our behavioral studies examine the effects of odorant chemical structure, receptor biophysics and prior experience on olfactory sensation and perception. Current and recent electrophysiology projects utilize single cell, multi-cell, and
population recordings in one or more of the olfactory bulb, amygdala, pyriform cortex, entorhinal cortex, hippocampus, and visual cortex while animals perform simple and complex olfactory discrimination tasks, forage, and solve odor- or visual-cued mazes. We have shown that activity from the hippocampal system and other parts of the limbic system strongly influence that seen in the most peripheral structure of the olfactory CNS, the olfactory bulb. This influence is seen at the level of single neurons and in the oscillatory coupling of small to large groups of neurons, dependent on the difficulty of the odor discrimination task. This modulation is associated with changes in oscillatory state (gamma or beta oscillations) and functional connectivity among parts of this highly distributed and interconnected system. These changes can be driven by synaptic and neuromodulatory inputs from central brain areas, as well as changes in sniffing behavior. Thus, the personal internal and behavioral states of an animal can influence sensory processing at a very early stage.
Techniques include operant behavior, local field potential recording and analysis of oscillatory signals, multi- and single unit neural recording and analysis, optogenetic activation and inactivation, computational modeling, and pharmacological manipulations.
A new area of research poses cognitive and physiological questions that are addressed in human subjects. These are primarily behavioral studies here at the University of Chicago and physiological studies in collaboration with colleagues at other institutions.