# Reward Value Encoding of Dynorphin and Enkephalin Neurons in Medial Accumbens Shell

> **NIH NIH F31** · UNIVERSITY OF WASHINGTON · 2020 · $37,950

## Abstract

Project Summary:
The primary goal of this training proposal is to dissect the neurocircuitry of medial nucleus accumbens shell
(mNAcSh) dynorphin and enkephalin neurons in reward processing. By local interconnectivity and through output
projections to lateral hypothalamus (LH), ventral pallidum (VP) and ventral tegmental area (VTA), these neuronal
populations may process reward value and orchestrate activity of downstream limbic circuitry to coordinate
consummatory behavior and reinforcement. The first aim of this training proposal seeks to characterize the
neural activity of dynorphin and enkephalin neuronal populations in mNAcSh during the anticipation and
consumption of reward. Aim 1A uses in vivo 2-photon microscopy to observe the endogenous activity of
dynorphin and enkephalin neurons with single cell resolution during consumption of sucrose reward of varying
concentrations, while Aim 1B leverages the same approach to observe endogenous neural activity during cue-
reward associative learning. Aim 2A seeks to determine the molecular identity of these mNAcSh neurons that
project downstream to LH, VP and VTA through retrograde tracing techniques and fluorescent in situ
hybridization. Aim 2B uses multisite in vivo fiber photometry to simultaneously record the neural activity of
mNAcSh neuron axonal terminals in LH, VP and VTA during the consumption of sucrose reward of varying
concentrations and during cue-reward associative learning. Aim 3 leverages time-locked optogenetic
manipulations to establish necessity and sufficiency of observed endogenous neural activity of mNAcSh axonal
terminals in LH, VP and VTA in determining rate of sucrose consumption and rate of cue-reward associative
learning. This will be the first study to use in vivo calcium imaging in mNAcSh, fiber photometry of mNAcSh
output projections and time-locked optogenetic manipulation of these circuits to further understand the role of
this brain region and its output circuitry in reward processing. Leveraging new, high-resolution approaches will
allow us to further understand this critical endogenous opioid system and to identify potential mechanisms that
underlie addiction. During my training period, I will learn novel optical imaging, optogenetic, tracing and
behavioral techniques, as well as pursue my specific career development plan to prepare me for independence
as an academic researcher.

## Key facts

- **NIH application ID:** 9990031
- **Project number:** 1F31DA051124-01
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** CHRISTIAN PEDERSEN
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $37,950
- **Award type:** 1
- **Project period:** 2020-06-16 → 2021-04-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9990031

## Citation

> US National Institutes of Health, RePORTER application 9990031, Reward Value Encoding of Dynorphin and Enkephalin Neurons in Medial Accumbens Shell (1F31DA051124-01). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/9990031. Licensed CC0.

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