# Self-administration of fentanyl and methamphetamine vapor using a novel e-cigarette puff delivery system

> **NIH NIH R21** · VIRGINIA COMMONWEALTH UNIVERSITY · 2020 · $194,063

## Abstract

Use of E-cigarette (ECs) devices has increased dramatically over recent years. Newly developed high-output
ECs have the potential to delivery a variety of highly addictive drugs in addition to nicotine. Since inhalation
produces nearly instantaneous CNS access it raises the alarming possibility that both opioid and psychomotor
stimulant abuse by vaping may become serious public health concerns. However, at this time little is known
about the reinforcing effects of drugs, other than nicotine, delivered using ECs and appropriate animal models
are lacking. The present proposal seeks to fill this vacuum using a newly developed rodent vapor-puff delivery
self-administration system to assess the reinforcing effects of fentanyl (FEN) and methamphetamine (METH)
vapor. We will utilize the well-established fading principle to engender self-administration of FEN or METH
vapor in separate groups of male and female rats. Rats will initially be trained in daily 1-hr operant sessions to
emit lever responses in order to activate a nose poke device for delivery of a sweetened milk solution. The
dipper cup delivering the milk will be elevated into the vapor delivery aperture thereby bringing the rat's nose
into contact with vapor puffs. Over successive daily training sessions, 3 sec exposures to increasing
concentrations of FEN or METH in e-juice vapor (50% vegetable glycerol/49% propylene glycol/1% yellow
cake flavor) will occur concurrently with milk reinforcer presentation. Once behavior for the combination of the
liquid reinforcer and vaped FEN or METH has reached stable, behaviorally-active levels we will discontinue the
paired administration of milk reinforcers through a gradual daily fading procedure until responding is
maintained by only FEN or METH vapor delivery. After vapor self-administration is established we will install
an additional vaporizer activated by the lever-presses on a second lever permitting the use of a choice
paradigm to examine the reinforcing effects of a range of FEN or METH concentrations. During dose-effect
curve testing, responses on one lever of the operant chamber, signaled by a solidly illuminated lever-light, will
occasion the opportunity to engage in nose-pokes that deliver drug-laden vapor whereas nose pokes following
a response on the opposite lever, signaled by a blinking lever-light, will deliver drug-free vapor acting as a
control that is identical in all respects aside from the presence of drug. As a second complimentary method of
assessing the reinforcing effects of FEN or METH vapor we will utilize a progressive ratio test procedure. In
addition to varying drug concentration we will parametrically explore the role of vaporizer output wattage in
modulating the reinforcing effects of drug vapor. Lastly, commercial e-juice is composed of flavors, vegetable
glycerol (VG) and propylene glycol (PG). The addition of flavor may play an important role in promoting and
maintaining self-administration. To test this hypothesis we...

## Key facts

- **NIH application ID:** 9960484
- **Project number:** 5R21DA048242-02
- **Recipient organization:** VIRGINIA COMMONWEALTH UNIVERSITY
- **Principal Investigator:** KEITH L SHELTON
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $194,063
- **Award type:** 5
- **Project period:** 2019-07-01 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9960484

## Citation

> US National Institutes of Health, RePORTER application 9960484, Self-administration of fentanyl and methamphetamine vapor using a novel e-cigarette puff delivery system (5R21DA048242-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9960484. Licensed CC0.

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