# Modeling nicotine/THC co-use

> **NIH NIH R21** · UNIVERSITY OF PITTSBURGH AT PITTSBURGH · 2021 · $196,145

## Abstract

Project Summary/Abstract
Polysubstance use (PSU) is extremely common, with the majority of substance use treatment seekers reporting
the use of multiple substances. Moreover, PSU is becoming increasingly common among adolescents and young
adults, with up to 30% of individuals in this age group reporting PSU. Not only is the prevalence of PSU high,
but the consequences of PSU are also thought to be worse than for individuals who use single substances. One
of the most common substances to be used with any other drug of abuse is nicotine. Marijuana and nicotine co-
use is particularly common, with higher overall incidence of marijuana use in the general population and up to
80% of marijuana users reporting that they also use nicotine. Recent epidemiological studies indicate that the
co-use of nicotine with THC containing products is increasing, particularly in youth, and those that use both drugs
at the same time have worse overall outcomes than those individuals that consume both, but on separate
occasions. Thus, there is a need to increase our understanding of the interactions between nicotine and THC,
including how they affect the reinforcing properties of each other, whether there are differences in neural
responses relative to each substance alone, and whether co-self-administration leads to increased propensity
for relapse-like behavior. Thus, in this R21 application, the labs of Drs. Mary Torregrossa and Alan Sved will
collaborate to investigate in Aim 1, how nicotine influences THC self-administration. We will examine both the
effect of nicotine on acquisition of THC self-administration and acute effects on established THC intake. We will
also determine if nicotine alters dopamine release and neural activity in response to THC in the nucleus
accumbens shell as a first step toward investigating how nicotine may alter the reinforcing effects of THC. In Aim
2, we will develop a dual catheter system to allow simultaneous intravenous self-administration of THC and
nicotine, with the additional goal of making the technique available to other labs interested in PSU research of
other drugs of abuse. In addition, we will begin to determine if PSU leads to different outcomes relative to mono-
substance use by comparing cue-motivated, relapse-like drug seeking behavior in a cue-induced reinstatement
test in rats that self-administered both THC and nicotine versus each substance alone. In both aims, we will
compare adolescent and adult groups of males and females to determine if outcomes are different based on age
and/or sex. In particular, we are interested in whether or not adolescents are particularly susceptible to the
reinforcement-enhancing effects of nicotine/THC combinations that might explain the increased incidence of
nicotine and cannabis co-use in youth. Overall, the outcomes of the project will provide the basis for future grant
applications that can further probe the neural mechanisms and long-term functional outcomes of PSU and its
treatm...

## Key facts

- **NIH application ID:** 10299843
- **Project number:** 1R21DA052663-01A1
- **Recipient organization:** UNIVERSITY OF PITTSBURGH AT PITTSBURGH
- **Principal Investigator:** Alan F Sved
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $196,145
- **Award type:** 1
- **Project period:** 2021-09-15 → 2023-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10299843

## Citation

> US National Institutes of Health, RePORTER application 10299843, Modeling nicotine/THC co-use (1R21DA052663-01A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10299843. Licensed CC0.

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