PBIO SEMINAR SERIES

Olfactory processing in the Drosophila antennal lobe

Wednesday - May 07, 2008
2008 Crill Lecture
1:30 pm
D-209

Rachel Wilson
Assistant Professor of Neurobiology Harvard Medical School
Speaker's website

Host: Stan Froehner

The Drosophila antennal lobe is a useful model microcircuit for investigating sensory processing. This circuit contains relatively small numbers of neurons, and genetic tools allow us to label identified types of first-order olfactory receptor neurons (ORNs) and second-order projection neurons (PNs). We can monitor in vivo odor responses in these neurons using electrophysiological recordings, and we use genetic tools and pharmacology to probe functional interactions between neurons in this circuit. We have found that weak ORN odor responses are amplified in postsynaptic PNs, but strong odor ORN responses are not amplified to the same degree. This mainly reflects synaptic and cellular nonlinearities intrinsic to each glomerulus. However, a portion of a PN's odor responsiveness is not systematically related to the response of its presynaptic ORNs. This reflects the existence of excitatory and inhibitory connections between different PN types. I will discuss the functional properties of these connections, and their implications for olfactory processing in this circuit.