Banerjee, A., Chae, H., Albeanu, D. F. (September 2016) Intensity Invariant Readout of Olfactory Bulb Output is Facilitated by a Specific Inter-glomerular Circuit. In: Association for Chemoreception Sciences (AChemS), 37th Annual Meeting, 22–25 April 2015, Bonita Springs, Florida.
Abstract
Perception is often invariant for stimulus identity (eg: face recognition) even when other stimulus features (eg: light levels) vary widely. In the mammalian olfactory system, little is known about the neural mechanisms that extract odor identity, while tolerating fluctuations in concentration. We hypothesized that a specific gain-control circuit in the olfactory bulb (OB) mediated by DAT+ cells, reformats the OB output to facilitate efficient read- out of concentration-invariant odor identity by target cortical areas. To test this, we monitored the activity of numerous OB output (Mitral/Tufted) cells to odors across varying concentrations (3 orders of magnitude) using 2-photon microscopy. Individual mitral cells exhibited a diverse range of concentration response profiles (CRFs) - some monotonically increased, or decreased with increasing concentration, while others peaked at intermediate concentrations. Importantly, the mean population response increased only modestly across this large concentration range. A simple model assuming divisive normalization implemented by the DAT+ cells was able to generate the diversity of the experimentally observed CRFs. We visualized the neural population trajectories using PCA and found that for a given odor, all sampled concentrations spanned low- dimensional manifolds. Additionally, across a large odor panel, mitral cells exhibited significantly larger dimensionality compared to that of tufted cells, highlighting the differences between these two OB output channels. To assess the ability of cortical targets to correctly identify odors, we trained a linear decoder with sparse and non-negative weights to classify odor identity irrespective of concentration. The cross- validated performance was >80%, which significantly dropped when DAT+ cells were specifically ablated. We conclude that a specific interneuron circuit in the glomerular layer formats the OB population output so as to facilitate concentration invariant odor identification by the cortex. This may be the first of many such transformations that ultimately lead to perceptually stable behavior. Funding Acknowledgements: RO1 (NIH), CSHL startup, Crick-Clay graduate fellowship for AB.
| Item Type: | Conference or Workshop Item (Poster) |
|---|---|
| Additional Information: | Meeting Abstract |
| Subjects: | Publication Type > Meeting Abstract organs, tissues, organelles, cell types and functions > cell types and functions > cell types > neurons > neuronal circuits organs, tissues, organelles, cell types and functions > cell types and functions > cell types > neurons > neuronal circuits organs, tissues, organelles, cell types and functions > cell types and functions > cell types > neurons > neuronal circuits organs, tissues, organelles, cell types and functions > tissues types and functions > olfactory bulb |
| CSHL Authors: | |
| Communities: | CSHL labs > Albeanu lab |
| Depositing User: | Matt Covey |
| Date: | September 2016 |
| Date Deposited: | 28 Oct 2016 15:53 |
| Last Modified: | 22 Oct 2025 18:32 |
| URI: | https://repository.cshl.edu/id/eprint/33815 |
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