# Development of NMDA receptor subunits with alcohol insensitivity but unaltered physiology as molecular tools

> **NIH NIH R03** · MARQUETTE UNIVERSITY · 2022 · $76,500

## Abstract

The long term goal of this study is to understand the role of NMDA receptors (NMDAR) in the actions of alcohol
on the brain. Although NMDAR are known to be major CNS targets of alcohol action, the precise roles of
NMDAR and their substituent subunits in mediating the effects of alcohol are still incompletely understood.
Prior studies using pharmacological agents or molecular biological techniques such as “knockout” or “knock-in”
animals have been hindered by limitations including incomplete drug specificity and severe complications due
to alterations in receptor physiology associated with mutations at alcohol-sensitive amino acid positions. Work
from this laboratory has identified and characterized amino acid positions in the third and fourth membrane-associated (M) domains of the NMDAR GluN2A-C subunits that influence both ion channel gating and alcohol
sensitivity. Our observations that changes observed in ion channel gating are not directly linked to changes in
ethanol sensitivity (e.g., opposite changes in ion channel gating measures can similarly affect ethanol
sensitivity) are consistent with the idea that alcohol sensitivity and gating may be regulated separately. Our
recent work has shown that multiple mutations at alcohol-sensitive positions can retain low alcohol sensitivity
while improving gating characteristics, and in preliminary studies, we have identified a mutation in the ligand-binding domain (LBD) that can further restore native physiological characteristics to an alcohol-insensitive
GluN2A subunit. In these studies we will use site-directed mutagenesis combined with whole-cell and
macropatch concentration-jump patch-clamp recording to test the hypothesis that NMDAR subunits with
altered ethanol sensitivity but essentially normal physiology can be developed by introducing multiple
mutations at positions regulating alcohol sensitivity, ion channel gating, and/or ligand binding. To best define
the role of an NMDAR subunit in CNS alcohol actions, the ideal molecular tool would be an alcohol-insensitive
subunit that is otherwise normal with respect to its physiology. The purpose of this project is to circumvent the
shortcomings of currently-available methods by developing alcohol-insensitive NMDAR GluN2 subunits with
unaltered physiology for use as molecular tools, and to make these subunits available for use in
neurophysiological and behavioral studies by the neuroscience and alcohol research communities. The
knowledge gained from these studies could provide a basis for a better understanding of the precise role of the
NMDA receptor in the neurophysiological and behavioral effects of alcohol as well as in alcoholism.

## Key facts

- **NIH application ID:** 10494115
- **Project number:** 5R03AA028903-02
- **Recipient organization:** MARQUETTE UNIVERSITY
- **Principal Investigator:** ROBERT WILLIAM PEOPLES
- **Activity code:** R03 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $76,500
- **Award type:** 5
- **Project period:** 2021-09-25 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10494115

## Citation

> US National Institutes of Health, RePORTER application 10494115, Development of NMDA receptor subunits with alcohol insensitivity but unaltered physiology as molecular tools (5R03AA028903-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10494115. Licensed CC0.

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