Transformation of odor selectivity from projection neurons to single mushroom body neurons mapped with dual-color calcium imaging.

TitleTransformation of odor selectivity from projection neurons to single mushroom body neurons mapped with dual-color calcium imaging.
Publication TypeJournal Article
Year of Publication2013
AuthorsLi H, Li Y, Lei Z, Wang K, Guo A
JournalProceedings of the National Academy of Sciences of the United States of America
Volume110
Issue29
Pagination12084-9
Date Published2013 Jul 16
Abstract

Although the response properties of most neurons are, to a large extent, determined by the presynaptic inputs that they receive, comprehensive functional characterization of the presynaptic inputs of a single neuron remains elusive. Toward this goal, we introduce a dual-color calcium imaging approach that simultaneously monitors the responses of a single postsynaptic neuron together with its presynaptic axon terminal inputs in vivo. As a model system, we applied the strategy to the feed-forward connections from the projection neurons (PNs) to the Kenyon cells (KCs) in the mushroom body of Drosophila and functionally mapped essentially all PN inputs for some of the KCs. We found that the output of single KCs could be well predicted by a linear summation of the PN input signals, indicating that excitatory PN inputs play the major role in generating odor-selective responses in KCs. When odors failed to activate KC output, local calcium transients restricted to individual postsynaptic sites could be observed in the KC dendrites. The response amplitudes of the local transients often correlated linearly with the presynaptic response amplitudes, allowing direct assay of the strength of single synaptic sites. Furthermore, we found a scaling relationship between the total number of PN terminals that a single KC received and the average synaptic strength of these PN-KC synapses. Our strategy provides a unique perspective on the process of information transmission and integration in a model neural circuit and may be broadly applicable for the study of the origin of neuronal response properties.

DOI10.2147/IJN.S37140
Alternate JournalProc. Natl. Acad. Sci. U.S.A.