# CRCNS: Odor processing by cortical neural circuits

> **NIH NIH R01** · DUKE UNIVERSITY · 2020 · $178,794

## Abstract

Project Summary
The enormous diversity of neural cell types is a defining characteristic of the brain. Different 
neural circuits consist of a myriad of distinct cell types, each with specific intrinsic properties 
and patterns of synaptic connectivity, which transform neural input and convey this information to 
downstream  targets. However, despite their fundamental importance in neural processing, our 
understanding of how individual cell types differentially contribute to neural circuit function and 
computation remains poor. Here, the investigators leverage a highly tractable neural circuit, the 
mouse olfactory (piriform, PCx) cortex, to determine how information about odor stimuli is encoded, 
transformed, and conveyed to its different downstream target areas. The objective of this proposal 
is to register diverse odor responses observed in PCx neurons onto identified neural cell types, 
defined by their morphology, intrinsic properties, and connectivity. This will be achieved via a 
collaborative, multidisciplinary, iterative computational-experimental approach, involving 
computational modeling, in vivo two­ photon imaging, in vitro electrophysiology, behavior, 
chemogenetics and decoding analyses. The investigators' working hypothesis is that different 
features of an odor - its identity, intensity, and valence - are selectively extracted and encoded 
by distinct subsets of PCx neurons by virtue of their different intrinsic and local circuit 
properties, and then selectively transmitted to different target areas.
In the two aims proposed, the investigators will image activity evoked by different odorants at 
multiple concentrations in subpopulations of PCx neurons in awake, behaving mice. They will compare 
their imaging data with simulated odor-evoked activity in a computational model in which they 
incorporate the specific intrinsic properties and patterns of local synaptic connectivity of these 
subpopulations of PCx neurons. In Aim1, the investigators will image and model odor responses in 
two morphologically distinct subtypes of principal neurons, semilunar cells and superficial 
pyramidal cells. In Aim 2 they use a similar approach, but with subpopulations of PCx neurons 
defined by their specific projection targets. Mice will be performing a go/no go odor 
discrimination task during imaging, allowing characterization of responses to odors with different 
identities, concentrations or valence. This experimental-computational approach will determine the 
extent to which the distinct intrinsic properties and specific connectivity patterns of different 
cell-types accounts for differences in their odor responses. Crucially, mismatches between modeling 
and experimental results will reveal additional properties of these cells and circuitry that may 
determine their odor responses, which can and will be tested experimentally. Achieving the goals of 
this proposal will therefore provide a coherent framework for understanding how differ...

## Key facts

- **NIH application ID:** 9954068
- **Project number:** 5R01DC016782-04
- **Recipient organization:** DUKE UNIVERSITY
- **Principal Investigator:** Kevin Franks
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $178,794
- **Award type:** 5
- **Project period:** 2017-07-01 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9954068

## Citation

> US National Institutes of Health, RePORTER application 9954068, CRCNS: Odor processing by cortical neural circuits (5R01DC016782-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9954068. Licensed CC0.

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