# Cellular basis for morphine-induced itch

> **NIH NIH F31** · UNIVERSITY OF PITTSBURGH AT PITTSBURGH · 2020 · $50,520

## Abstract

Project Summary/Abstract
Itch is a prevalent and debilitating side effect that follows neuraxial (intrathecal and epidural) morphine
administration and has limited the therapeutic potential of opioids for pain. Nevertheless, the cellular basis of
morphine-induced itch remains unclear. Morphine acts at the mu opioid receptor (MOR) to inhibit neuronal
activity. Thus, it follows that morphine can cause itch through inhibition of inhibitory neurons that gate itch. I
seek to test the hypothesis that neuraxial morphine causes itch through disinhibition. I propose to determine
which subtype(s) of spinal interneurons is/are responsible for morphine-induced itch. There are five distinct
subtypes of inhibitory neurons in the spinal cord dorsal horn that can be distinguished using distinct
neurochemical markers and targeted with specific Cre alleles. Of these, two have previously been implicated in
the inhibition of itch and are, therefore, ideal candidates. I propose to identify which of these five populations is
responsible for morphine-induced itch using a combination of behavioral, anatomical, and physiological
approaches. My proposal comprises the following aims: Aim 1: Determine whether the expression of MOR in
spinal inhibitory neurons is required for morphine-induced itch. Aim 2: Determine which cell types express
MOR. Aim 3: Determine which cell types are inhibited by morphine. Together, these experiments could reveal
the cellular basis for morphine-induced itch for the first time. This information is critically important because a
better understanding of how morphine causes itch in the spinal cord can lead to improved treatments for pain
that do not cause itch. Thus, this work integrates closely with my clinical interest in anesthesiology. In this
proposal, I outline a combination of rigorous mentored research training, longitudinal clinical experiences,
coursework, and professional and leadership development activities. The intellectual, technical, and
professional skills refined during this fellowship training period will be instrumental in my development as an
aspiring physician scientist in the clinical field of academic anesthesiology.

## Key facts

- **NIH application ID:** 10019345
- **Project number:** 5F31NS113371-02
- **Recipient organization:** UNIVERSITY OF PITTSBURGH AT PITTSBURGH
- **Principal Investigator:** Eileen Nguyen
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $50,520
- **Award type:** 5
- **Project period:** 2019-09-01 → 2021-09-02

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10019345

## Citation

> US National Institutes of Health, RePORTER application 10019345, Cellular basis for morphine-induced itch (5F31NS113371-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10019345. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*