Inhibitory neurons play critical roles in regulating and shaping olfactory responses in vertebrates and invertebrates. In insects, these roles are performed by relatively few neurons, which can be interrogated efficiently, revealing fundamental principles of olfactory coding. Here, with electrophysiological recordings from the locust and a large-scale biophysical model, we analyzed the properties and functions of GGN, a unique giant GABAergic neuron that plays a central role in structuring olfactory codes in the locust mushroom body. Our simulations suggest that depolarization of GGN at its input branch can globally inhibit KCs several hundred microns away. Our in vivo recordings show that GGN responds to odors with complex temporal patterns of depolarization and hyperpolarization that can vary with odors and across animals, leading our model to predict the existence of a yet-undiscovered olfactory pathway. Our analysis reveals basic new features of GGN and the olfactory network surrounding it.
Traced neuronal morphology have been deposited on neuromorpho.org and they are currently being processed by the repository. Identical morphology data along with the computational models and simulation scripts are available on GitHub (https://github.com/subhacom/mbnet). Model source code curated in Model DB is available under the accession number 262670.
- Subhasis Ray
- Zane N Aldworth
- Mark A Stopfer
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
- Kristin Scott, University of California, Berkeley, United States
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