# Multiplex interrogation of neuromodulatory signaling in behaving animals with enhanced depth and resolution

> **NIH NIH U01** · UNIVERSITY OF CALIFORNIA AT DAVIS · 2022 · $863,993

## Abstract

Project Summary
The dynamic adaptability of the mammalian brain to environmental changes is remarkable, as it is the complexity
of the networks of neurons underlying the operations that allow for such adaptations. Although we have some
understanding of the anatomical and functional basis of this, we are still lacking a detailed picture of how the
modulation of neuronal activity works. What is the timing and locations of these neuromodulator release and
relationship with excitatory/inhibitory circuits? How does the neuromodulators circuitry accomplish the regulation
of firing and synaptic properties of targeted neurons? Filling these gaps in knowledge would advance our
understanding of all aspects of neuromodulator biology and allow discovery of new therapeutic strategies. To
help close this gap, we have used creative approaches to the development of genetically encoded to directly
report behaviorally triggered and modulated neuromodulator release including serotonin (5-HT), dopamine (DA)
and norepinephrine (NE). We have disseminated these indicators to the neuroscience community and spurred
major discoveries of novel mechanisms regulating neuromodulator release underlying motivation and addiction.
Build on this initial success, we propose to further expand the effectiveness of this toolbox of NM sensors to
enable imaging sparse release at depth and subcellular resolution. Our specific goals are to (1) improve the
sensitivity of our current sensors to enable robust imaging of sparse neuromodulator release, push their spatial
resolution to the subcellular level and increase linearity of response at lower concentrations; (2) expand their
spectral range to red/far-red to enhance imaging depth, SNR and in vivo multiplex measurement and
manipulation of multiple circuit components using two or three distinct colors, and (3) characterize the possible
interference of current sensors with endogenous signaling and systematically validate emerging sensors with a
wide-ranging microscopy approaches in vivo. Our strategy relies on a dynamic collaboration between the sensor
design team and end users to obtain continuous feedback to implement efficient improvements to the sensors.
It is our goal to rapidly disseminate a wide range of well-characterized, highly sensitive indicators for the
neuroscience community to be employed to study behaving mice, fish, flies and worms, to enrich our knowledge
on the functional roles of neuromodulators in the brain circuitry.

## Key facts

- **NIH application ID:** 10400216
- **Project number:** 5U01NS120820-02
- **Recipient organization:** UNIVERSITY OF CALIFORNIA AT DAVIS
- **Principal Investigator:** Lin Tian
- **Activity code:** U01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $863,993
- **Award type:** 5
- **Project period:** 2021-05-01 → 2025-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10400216

## Citation

> US National Institutes of Health, RePORTER application 10400216, Multiplex interrogation of neuromodulatory signaling in behaving animals with enhanced depth and resolution (5U01NS120820-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10400216. Licensed CC0.

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