# Circuitry and function of the NLOT in olfactory-guided behaviors

> **NIH NIH R21** · UNIVERSITY OF PENNSYLVANIA · 2022 · $162,500

## Abstract

Project Summary
The sense of smell plays critical roles in mediating a variety of behaviors in animals including humans. Odor
molecules activate olfactory sensory neurons (OSNs) in the nose, which carry the information to the olfactory
bulb (OB) and subsequently to the olfactory cortical regions including the piriform cortex and anterior olfactory
nucleus/tenia tecta (AON for simplicity). The connectivity of olfactory cortices to their downstream targets is
presumably important for olfactory-guided behaviors, but little is known about anatomical connections and
functional properties of these downstream targets. One such structure is the nucleus of lateral olfactory tract
(NLOT), which connects reciprocally with some cortical and limbic areas and is implicated in olfactory-guided
behaviors. We recently discovered that the NLOT is a major downstream target of the AON via anatomical
tracing in a novel mouse line, which allows genetic access to AON neurons. In addition, we verified functional
connectivity of this pathway since AON neurons make excitatory monosynaptic connections onto NLOT
neurons. Further, ablation of glutamatergic NLOT neurons led to severe deficits in olfactory guided behaviors.
The preliminary studies lead to the hypothesis that the NLOT is an essential neuroanatomical structure in an
olfactory circuit that is critical for odor-guided behaviors. Multidisciplinary approaches (circuit tracing, in vitro
electrophysiology, pharmacology, optogenetics, chemogenetics, in vivo fiber photometry, and behavior) will be
used to pursue three specific aims. We will (1) delineate anatomical and functional inputs to NLOT neurons, (2)
determine in vivo activity of NLOT neurons during olfactory-guided behaviors, and (3) determine loss-of-
function effects of NLOT neurons on olfactory-guided behaviors. Overall, the current study will provide critical
insights into the NLOT neural circuitry and its role in olfactory-guided behaviors.

## Key facts

- **NIH application ID:** 10290313
- **Project number:** 5R21DC019193-02
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Janardhan Prasad Bhattarai
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $162,500
- **Award type:** 5
- **Project period:** 2020-12-01 → 2023-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10290313

## Citation

> US National Institutes of Health, RePORTER application 10290313, Circuitry and function of the NLOT in olfactory-guided behaviors (5R21DC019193-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10290313. Licensed CC0.

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