# Modulation of social behavior by mu opioid receptors in the nucleus accumbens

> **NIH NIH F31** · UNIVERSITY OF MINNESOTA · 2020 · $32,627

## Abstract

Project Summary
Sociability encompasses a range of complex behaviors that require coordinated activity of multiple neural circuits
for successful expression. Effective social engagement is highly rewarding and relies upon mu opioid receptor
signaling within the nucleus accumbens, an important reward center of the brain. Selective blockade of the mu
opioid receptor within the nucleus accumbens suppresses social interactions whereas the stimulation of these
receptors significantly increases social interactions. As mu opioid receptors are expressed on presynaptic axon
terminals as well as a variety of postsynaptic cells in the nucleus accumbens, the mechanisms by which mu
opioid receptors control social responding remains unclear. Therefore, the broad objective of this proposal is to
understand how mu opioid receptors on nucleus accumbens microcircuitry mediate social behavior. The focus
of this proposal will be on the medium spiny projection neurons, which constitute the primary cell type of the
nucleus accumbens. Medium spiny neurons are distinguished by their expression of Drd1 or Drd2 dopamine
receptor subtypes, and activation of these different cell types has distinct effects on reward-related behavioral
output. In this proposal I will selectively manipulate the expression of mu opioid receptors on medium spiny
neuron sub-types and characterize the resultant cellular and social phenotype (Aim 1). Additionally, I will use
chemogenetics to restore inhibitory modulation of specific medium spiny neuron subtype following mu opioid
receptor deletion, and determine the impact on social behavior (Aim 2). This project will clarify how mu opioid
receptor activity changes medium spiny neuron activity dynamics in the nucleus accumbens in a manner
necessary for social behavioral expression. Through my training I will acquire the background, conceptual and
technical knowledge to complete this proposal. My sponsor, Dr. Patrick Rothwell, and co-sponsor, Dr. Kevin
Wickman, provide outstanding mentorship, focused on my technical and professional development as a
neuroscientist. In addition, the University of Minnesota Graduate Program in Neuroscience offers a supportive
and collaborative scientific environment and has numerous Core Facilities that will be available to me for training
and equipment use. The proposed project will help me become an independent research scientist as I develop
the ability to identify and interrogate cellular, circuit and behavioral abnormalities that arise in neuropsychiatric
diseases.

## Key facts

- **NIH application ID:** 9992147
- **Project number:** 1F31MH122094-01A1
- **Recipient organization:** UNIVERSITY OF MINNESOTA
- **Principal Investigator:** Carlee Toddes
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $32,627
- **Award type:** 1
- **Project period:** 2020-03-02 → 2022-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9992147

## Citation

> US National Institutes of Health, RePORTER application 9992147, Modulation of social behavior by mu opioid receptors in the nucleus accumbens (1F31MH122094-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9992147. Licensed CC0.

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