- Dopamine is a feel-good neurotransmitter known as "the reward molecule." Dopaminergic pathways are activated by goal-oriented behavior.
- Neuroscientists have long known that achieving extrinsic goals or winning a prize triggers a surge in dopamine levels.
- New treadmill-based research (2021) shows that trained mice can learn to willfully modulate dopamine impulses to receive a reward.
"Making your bed in the morning can be a dopamine releaser if you acknowledge it as such. Set up the playing field every day to release dopamine by setting lots of mini-goals and achieving them. Setting goals and achieving them guarantees a constant supply of dopamine, which is released during goal-oriented behavior and upon achieving a goal. Finish what you start, and you'll release dopamine." —Christopher Bergland, The Athlete's Way (2007)
Since the aughts, when I researched and wrote The Athlete's Way: Sweat and the Biology of Bliss, I've been on the lookout for science-based evidence that gives us fresh clues about how to trigger the release of feel-good neurotransmitters on demand via exercise and day-to-day lifestyle habits.
This week, a new treadmill-based study (Foo et al., 2021) of mice reports that in addition to dopamine being released after achieving a goal, dopaminergic activity can be "ramped up" willfully when a treadmill-running mouse is trained to receive a reward for learning to modulate its "spontaneous impulses" of dopamine on demand. These findings were published on July 23 in the peer-reviewed journal Current Biology.
Willfully Triggering Dopamine Release Can Become a Prize Unto Itself
In this first-of-its-kind experiment, UC San Diego's Conrad Foo, along with colleagues from the Icahn School of Medicine at Mount Sinai in New York, investigated whether laboratory mice could willfully control spontaneous dopamine pulses that typically occur in the mouse brain when mice use self-initiated movements to navigate for a reward.
On average, the researchers found that "spontaneous impulses of dopamine occur in the cortex of mice at a rate of approximately 0.01 per second."
Foo et al.'s ultimate goal was to answer the research question: "Can mice be trained to change the amplitude and/or timing of dopamine events triggered by internal brain dynamics, much as they can change the amplitude and timing of dopamine impulses based on an external cue?"
To answer this question, they designed a unique treadmill set up in a research lab that allowed neuroscientists to monitor dopamine levels in a mouse's cortex as it was moving. The researchers reinforced a learning paradigm that rewarded treadmill-running mice for increasing dopamine levels in the brain using their own volition.
In this experiment, willfully increasing dopamine while running on a treadmill was reinforced with the prize of a "sucrose drop reward." Real-time feedback of how a mouse's brain responded to these rewards made it possible to teach mice how to self-regulate their cortical dopamine levels.
After just a few practice sessions, the researchers found that trained mice could volitionally modulate spontaneous dopamine impulses while moving on a treadmill.
"Our results highlight the potential role of internal brain dynamics in modulating as well as creating the spontaneous dopamine events," Foo et al. conclude. "We observed that reinforcement learning may be used to train animals to initiate extrasynaptic impulses of dopamine in return for a reward."
3 Tips for Willfully Controlling Your Dopamine
Science-Based Knowledge Is Power. Knowing that the mammalian brain can willfully modulate spontaneous cortical dopamine impulses makes it easy to imagine that you can self-produce dopamine spikes in your cortex on demand. (If mice can do it, so can you!) Even if this is just a placebo effect at first, believing that you're willfully increasing dopamine levels could create a self-fulfilling prophecy with continuous training.
Set Mini-Goals, Achieve Them. Setting mini-goals that are easily achievable by breaking down larger tasks into doable doses can turn your brain into a turbo-charged dopamine factory. Again, knowing that accomplishing each mini-goal will give you a "hit" of dopamine may reinforce your ability to control spontaneous dopamine impulses in your cortex volitionally.
Celebrate Small Wins. Patting yourself on the back after each "micro win" and saying "YES! I did it!" may reinforce personalized learning links to willfully controlling self-administered "hits" of dopamine — especially if you make releasing dopamine a goal (and a prize) in and of itself.
Although neuroscientists have known for decades that achieving a goal and being able to say "YES! I did it!" gives people that jubilant three-cherries-in-a-row jackpot feeling, the latest research (2021) in mice suggests that the mammalian brain can also willfully trigger an uptick of dopamine when increasing dopamine (in and of itself) becomes a rewarded prize.
Therefore, in addition to setting lots of mini-goals throughout the day and achieving each one—so you get lots of feel-good dopamine surges—you can also look at creating these dopamine spikes as something you're doing volitionally that will make you feel good.
Interval Training Makes It Easier to Self-Administer "Micro-Doses" of Dopamine
When structuring your daily cardio workouts, instead of just doing continuous moderate exercise (CME) that might only give you one big hit of dopamine at the end of a long stretch, break up the workout with some moderate-to-vigorous aerobic interval training (AIT) or high-intensity interval training (HIIT); both AIT and HIIT will release lots of microdoses of dopamine during a cardio workout.
Evidence-based research suggests that you can probably create your own "reinforced learning paradigm" by imagining that the feel-good sensations of completing each interval of AIT or HIIT are accompanied by a spike in dopamine that neuroscientists could see if you were being monitored in a lab.
For example, try six 3-minute intervals of higher-intensity exercise followed by 2-minute recovery periods at lower-intensity during a 30-minute session of AIT or HIIT. By doing this, you'll get six hits of willfully modulated dopamine that will make you feel like a champ and continuously reinvigorate your motivation throughout the half-hour workout.
Conversely, if you do cardio at the exact same pace or level of exertion for the entirety of a 30-minute CME session—without consciously creating little dopamine-inducing "molehills" of victory—you'll only get one "macro hit" of dopamine when the half-hour workout is complete. Also, this psycho-neurobiological monotony might cause you to lose your oomph halfway through and start lollygagging after 15 minutes.
Armed with the knowledge that mice can willfully cause a surge in dopamine levels when they're rewarded for doing so, it seems highly likely that humans also have the ability to "volitionally control their spontaneous impulses" of dopamine. That said, more research is needed to validate precisely how "reinforcement learning links spontaneous cortical dopamine impulses to reward" in humans.
Conrad Foo, Adrian Lozada, Johnatan Aljadeff, Yulong Li, Jing W. Wang, Paul A. Slesinger, David Kleinfeld. "Reinforcement Learning Links Spontaneous Cortical Dopamine Impulses to Reward." Current Biology (First published: July 23, 2021) DOI: 10.1016/j.cub.2021.06.069