# Innovation of methods for in vivo monitoring and manipulation of neurotensin circuits

> **NIH NIH R21** · UNIVERSITY OF WASHINGTON · 2020 · $233,250

## Abstract

Project Summary/Abstract
Neuropeptides are essential modulators of neural circuits governing a wide variety of behaviors including
eating, drinking, stress, learning, and reward. While previous genetic and pharmacological studies have
provided critical insight into the underlying principles governing peptide function, technical limitations have
constrained our ability to effectively probe peptidergic circuits, and many questions remain unanswered.
Notably, peptidergic neurons commonly release more than one neuropeptide, and also typically release one
fast neurotransmitter, such as glutamate or GABA. Current genetic mouse models and viral tools are unable to
effectively and efficiently separate these different neurotransmitter and neuropeptide components. Here I
propose to use the neurotensin (NTS) projections from the lateral hypothalamus (LH) to the ventral tegmental
area (VTA) as a model peptidergic circuit for the development of novel viral tools that will enable real-time
monitoring of peptide release and rapid cell-type specific knockout of peptide-related genes. NTS is known to
interact with dopamine neurons in the VTA to promote appetitive behaviors, and we have found that stimulation
of NTS projections from the LH to the VTA initiates consumptive and appetitive behavioral phenotypes. These
neurons release GABA in addition to NTS, and it is unclear what role each of these transmitter components
plays in directing the observed behaviors. We have developed a single-vector conditional viral CRISPR/Cas9
system that enables rapid knockout of any given gene in a cell-type specific manner with high efficiency. I
propose to use this system to knock out the gene encoding NTS (Nts) or the gene encoding the vesicular
GABA transporter Vgat (Slc32a1) in LH NTS neurons, and will test how removing either component affects the
behaviors induced by stimulation of this circuit. I will also use this viral CRISPR method to target NTS
receptors in the VTA. In addition, I propose to validate a fluorescent sensor for NTS and use this tool in vivo to
monitor peptide release in real time in mice undergoing appetitive behaviors. Completion of this proposal will
answer critical biological questions about NTS regulation of behavior via its modulation of the dopamine
system and will establish feasibility for generating new viral-based tool kits that can be applied to investigate
peptidergic circuits throughout the brain.

## Key facts

- **NIH application ID:** 9873323
- **Project number:** 1R21MH121774-01
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** Marta E Soden
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $233,250
- **Award type:** 1
- **Project period:** 2019-12-01 → 2021-10-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9873323

## Citation

> US National Institutes of Health, RePORTER application 9873323, Innovation of methods for in vivo monitoring and manipulation of neurotensin circuits (1R21MH121774-01). Retrieved via AI Analytics 2026-06-11 from https://api.ai-analytics.org/grant/nih/9873323. Licensed CC0.

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