OGDEN — Vaping is often in the headlines, but scientists are just starting to understand the effects of e-cigarette vapor on humans, particularly its addictive nature.

At Weber State University, a neuroscience lab made up of about 10 undergraduates is on the forefront of that effort. The group, divided into teams, is running several studies of vaping in mice and humans. They’re exploring two central questions — why e-cigarettes are addictive and what their long-term health effects are.

For the studies on mice, small groups of mice are placed in a “vape chamber,” a clear box somewhat larger than shoebox. A pump pushes vapor from a vaping cartridge into the chamber.

The vaping cartridges used in the research aren’t anything special — they were purchased from a local vape shop, said the group’s supervising professor, Todd Hillhouse, an assistant professor of neuroscience and psychology at Weber State and director of the university’s neuroscience program.

None of the group’s research currently examines the effects of vapor containing THC, Hillhouse said, though the student teams may take this on in the future.

In an ongoing study examining the effects of nicotine-free vapor on mouse behavior, the group is seeing results that are particularly relevant to teens, who are using e-cigarettes in increasing numbers.

As part of this study, the mice in the chamber are exposed to six three-second puffs of vapor over the course of two minutes.

“(This) seems somewhat comparable to what humans would do,” Hillhouse said. “In humans, the average puff is about four and a half seconds, and then the sessions are about 10 minutes.”

After being exposed to vapor in the vape chamber, the mice are placed in another box where their movement is observed. When they’re behaving normally, mice will stay near the walls of the box because the open, central area makes them feel more vulnerable to predators, Hillhouse said. However, after some time, they’ll venture into the center.

Mice who were exposed to vapor alone, without nicotine, moved less and spent more time along the walls, hesitating to explore the center to the same degree as mice behaving normally. This behavior is an indication of anxiety and sensitivity to the vapor, Hillhouse said.

“Without nicotine, just the puff itself, just vapor will decrease activity and then also produce anxiety,” Hillhouse said, “which is important ... There’s a lot of high school students who don’t vape the nicotine, they just vape flavor, and so there still is some type of change occurring, but we don’t know what yet.”

Precisely because researchers are still collecting evidence on vaping’s effects, Hillhouse cautions people to consider what isn’t yet known about vaping before choosing to do it.

“Just because (vaping) doesn’t have nicotine doesn’t mean it’s not harmful or not addictive,” Hillhouse said. “It’s not necessarily any better for you (than cigarettes).”

Hillhouse suspects that nicotine isn’t the main culprit in vaping’s long-term health effects, either, he said.

“Vaping is probably ... not healthy for you because you are vaping an oil, and your lungs are porous, and so oil can stick into your lungs and stay there,” he said.

Student researchers in the lab have completed one study on mice, finding that mice moved much more after inhaling low-dose nicotine vapor. This increased activity “is typically interpreted as drug-seeking behavior,” according to a description of the research provided by Hillhouse, so it’s an indication that the substance has addictive properties.

Earlier this week, the student research team over this completed project received notification that it was accepted for publication by the peer-reviewed journal Behavioral Pharmacology — signaling that it’s the caliber of research produced in neuroscience-related doctoral programs.

In a related study of humans, a student research team found that low-dose nicotine vapor from e-cigarettes resulted in “addiction-related responses” reported by e-cigarette users, according to a description provided by Hillhouse.

These responses were more significant than might be expected given the low dose of nicotine, according to a Weber State press release, suggesting that e-cigarette vapor does not contain enough nicotine to satisfy the cravings of regular e-cigarette users or that their cravings are driven by environmental cues — questions that the research team is now seeking to answer.

Both the completed projects were led by female Weber State students — Sarah Honeycutt and Makenzie Peterson (now graduated), respectively. Two more female students are leading two of the lab’s three ongoing projects.

All three of the students working in the lab when the Standard-Examiner visited were also women — Nicole Allen, Allyson Barraza and Megan Dewey — and they said they had plans to pursue graduate school in the field, likely to please the many institutions seeking to raise the number of women pursuing science-related careers.

The three students said the research experience has played a role in developing their interest in the area and helping them feel prepared to move forward in the field.

The lab is also, interestingly, made up of animal lovers — including Hillhouse.

During one project, a team pulled mice out of the vape chamber halfway through a planned 30-minute exposure because the mice were lethargic and not looking good, Hillhouse said. The group plans to explain this choice in the paper they hope to publish.

“I actually think that’s how all of us are in the group,” said Allen, a senior at Weber State, “which makes us better caretakers. We’re really particular about making sure our mice are always cared for, and we handle them as gently as we can.

“... In order for humans to be able to have medical treatment and information ... this (animal research) is an integral part of that,” Allen continued, “so that’s kind of how I look at it.”

Contact reporter Megan Olsen at molsen@standard.net or 801-625-4227. Follow her on Twitter at


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