There’s nothing quite like coming home and laying down in your bed after some time away. While this year has seen all of us spend more time at home than we were planning, under normal circumstances tons of people become homesick rather quickly while out on vacations or trips. There’s just something uniquely soothing about the familiarity and comfort one’s home provides.
Now, a new study just released by Florida Atlantic University has collected compelling evidence suggesting our minds actually release an extra dose of dopamine whenever we return home from a long day out or extended trip. Dopamine is a neurotransmitter that plays a big role in producing feelings of pleasure.
Conducted with a group of lab mice, researchers say their experiment suggests coming home produces about the same dopamine surge that a dose of cocaine would!
Each mouse was taken from their home cage and placed in another chamber for some time. When the mice were eventually returned, they showed a “rapid rise” in dopamine levels upon reaching home sweet home.
Importantly, the rodents didn’t display that same increase in dopamine if they were returned to a case that only looked like their home. Just like any of us would, the mice noticed if they were sent to an imposter “home.”
Dopamine is an extremely important part of a human’s larger “reward system.” Dopamine is released whenever someone eats food they enjoy, has sex, or engages in pretty much any activity or hobby they find enjoyable. Beyond just facilitating pleasure, dopamine plays a big role in humanity’s unique ability to plan, focus attention, and find motivation.
In both humans and rodents, dopamine is released within the nucleus accumbens brain region. So, for this study, a complex technique called fiber photometry was used to record moment-to-moment changes in the rodents’ nucleus accumbens during the experiments.
Dopamine is also heavily involved in substance abuse and addiction disorders, and the study’s authors believe their work provides new avenues to explore how exactly such issues develop.
“Our data provide clear evidence of a biochemical foundation for the reinforcing properties of home cage return. This simple environmental manipulation can provide a minimally-invasive approach to peel away aspects of reward circuitry connected to natural reinforcers – one that is critical to an animal’s survival,” says senior study author Randy Blakely, Ph.D., executive director of FAU’s Brain Institute and a professor of biomedical science in FAU’s Schmidt College of Medicine, in a release.
Moreover, similar experiments conducted with humans in the future represent a novel new way to measure people’s ability to feel pleasure in general.
“We think that monitoring the home cage-elicited release of dopamine provides a simple, but powerful paradigm for the study of how genetic and life events can lead to an inability to feel pleasure. The inability to feel pleasure is a major characteristic of mood disorders, and a simple test for the efficacy of medications or other treatments. The field of drug discovery needs simple, biomarker-based analogs of behavioral changes seen in people with mood disorders since we can’t ask a mouse how it feels,” Blakely notes.
There certainly may be an evolutionary aspect at play in all of this as well. Thousands of years ago humans were constantly on the move and the lookout for potential threats. Back then, a cozy and safe home would have sounded like heaven.
“We were struck as to how reliable the manipulation was in evoking dopamine release particularly when placed in the context of little or no rise in dopamine when the mice were moved from the home cage to the test chamber. We are excited now to see if the genetic models of brain disorders we study will impact this effect,” concludes lead study author Felix Mayer, Ph.D., a postdoctoral fellow in Blakely’s lab.
We’re all feeling cooped up this year. Perhaps these findings are a good idea to keep in mind the next time you’re feeling stir-crazy. There really is no place like home.
The full study can be found here, published in Neurochemistry International.