Neuroscientists are currently developing drugs derived from cannabidiol, one of the primary active compounds in cannabis, to treat chronic pain caused by brain injuries like concussions—the most common injury suffered by football players. Researchers suspect the same compounds also actively protect against chronic traumatic encephalopathy (CTE), the neurodegenerative disease caused by repeated brain trauma, which is at the center of football’s ongoing public health crisis.
Pennsylvania-based pharmaceutical startup Kannalife is leading the charge, armed with a federal patent awarded to the Department of Health and Human Services in 2003 proving that cannabidiol is a useful neuroprotectant. In February, the company published a study—designed with the help of Bennet Omalu, whom Will Smith portrayed in the 2015 film Concussion—which showed the synthetic cannabidiol prevents damage to diseased hippocampal neurons, the area of the brain responsible for learning and memory.
“One of the effects of cannabidiol is decreased inflammation,” explains Ronald Tuma, who leads Kannalife’s testing team at Temple University. “Cannabinoids can play a role in mitigating secondary nervous system trauma.” If this experimental treatment passes clinical trials, it could become the first U.S. neuroprotective drug, carrying the potential to treat everything from CTE to Alzheimer’s to poststroke pain syndrome.
Photo credit: Amber Star Merkens // Dance for PD – View of upturned face of Black woman with her arms extended, leading a chair dance class with lots of seniors sitting in the background extending their arms in the same motion.
Michaela Haas for Reasons to be Cheerful When musician David Byrne, the founder of Reasons to be Cheerful, performed at the sold-out Dolby Theatre in Los Angeles last fall, the entire crowd was on its feet for almost the entire show. They danced enthusiastically for nearly two hours straight, feeling a kind of unfiltered joy that’s…
When musician David Byrne, the founder of Reasons to be Cheerful, performed at the sold-out Dolby Theatre in Los Angeles last fall, the entire crowd was on its feet for almost the entire show. They danced enthusiastically for nearly two hours straight, feeling a kind of unfiltered joy that’s rare to access in everyday life.
The experience was a reminder of a long-dormant love of dance. The following month brought a sign-up for “Groove Therapy” with local dance teacher Leah Lynn. The youngest in our group is 16, the oldest over 70. Every Saturday, the class plays out a verb each participant brings to class — release, gather, resist, invite — translating abstract intentions into motion. It sounds faintly ridiculous. It is also disarmingly effective. Within minutes, something shifts. Stress loosens. Then for the next hour, the group learns hip-hop shuffles and swings their hips to Kool & the Gang or Beyoncé. The class ends with the same feeling each time: exhausted and exhilarated.
The dance classes provoked such a profound shift in mood as well as in the body that it was worth finding out if there was more to it.
Modern research is now increasingly suggesting that dance is medicine, a deeply effective intervention for physical, cognitive, and emotional health. Behind the feel-good performance lies hard science. On a purely physical level, dance improves cardiovascular fitness, strength, and coordination. In a longitudinal study, seniors who took part in regular dance training fell less often and were described as “physically better off and mentally fitter” than those in the control group.
Though the body benefits are impressive, the neurological ones are what make scientists lean forward. Dancing activates a wide network: auditory pathways, visual and motor cortex, the amygdala, and, above all, the somatosensory cortex and networks that keep track of where your body is in space. Each change in rhythm or melody is processed in milliseconds and translated into new steps, adjustments, and expressions, a form of real-time “multitasking” that pushes the brain harder than many other sports.
Nobody understands this better than the dozen people who gather for David Leventhal’s class at a dance studio in Brooklyn. Though it’s cold outside, Leventhal is conjuring a beach. “Visualize what that warmth feels like,” he says, brushing his hands over his arms as if applying sunscreen. “Can we take those waves in different directions, just like they do in the ocean?” Around him, a dozen bodies begin to ripple to the tune of the pianist in the room. Arms slice, float and curl through the air. For a moment, the bare white room is less clinic than coastline.
Leventhal, who danced for 13 years with the Mark Morris Dance Group, has spent the last quarter century leading a different kind of choreography: Dance for PD, a program for people living with Parkinson’s disease.
What began in Brooklyn in 2001 now reaches more than 30 countries and roughly 500 communities. Across the room, people who arrived with their shoulders slightly caved inward now stand taller. They trace arcs through space, step through a tango phrase, and turn what might otherwise register as tremor into jazz hands.
Participants in the program, which was created by the Mark Morris Dance Group and the Brooklyn Parkinson Group, routinely report better balance, more confidence walking, and a renewed sense of self. But just as often, they mention something less clinical and more essential: joy.
“I sometimes cannot walk, but I can dance,” participant Cyndy Gilbertson said in the documentary Capturing Grace. “The music leads, in other words; it’s not my brain telling me to take a step.”
You don’t need a severe diagnosis to benefit from dance. “Dance has been part of our human culture for millennia,” Leventhal points out. “It’s how we communicate, how we express emotion, how we find each other, how we build community.” Across cultures, from Indigenous North American traditions to Māori and Pacific Islander practices, dance has also long been intertwined with healing.
Over time, this seems to change the brain’s structure. A German study that followed older adults in a dance program for more than a year reported increases in gray matter volume and synaptic density in regions important for memory and executive function, along with preserved cognitive performance over five years of follow-up. The researchers found that dancing appeared to build “cognitive reserve” and was “the best prevention” against age-related cognitive decline in their cohort, with dancers showing a statistically lower risk of dementia than nondancers.
Those findings dovetail with a widely cited observational study: People who danced more than once a week had a 76% lower risk of developing dementia than those who danced less often, an association reported as stronger than that seen with many popular “brain games.”
“It’s a full-spectrum activity,” Leventhal explains. “It engages the body, cognition, emotion, and social connection — all supported by music.”
The real power, he argues, lies in the overlap. “The benefits come from the synergy among those domains.”
That synergy matters especially for Parkinson’s, which affects motor control, cognition, emotional expression and social engagement. Many people withdraw from public life as symptoms progress. “The beauty of this art form,” Leventhal says, “is that it’s a full-spectrum intervention for a full-spectrum condition.”
In a large meta-analysis of 55 randomized controlled trials in Parkinson’s disease, dance emerged as the most effective of nine exercise interventions for improving balance in that analysis, outperforming even advanced rehabilitation technologies. Styles like tango, waltz and foxtrot have been shown to improve gait speed and reduce falls.
While there is no cure for Parkinson’s, some early research suggests that dance can slow down the progression significantly for some people. “It’s early evidence,” Leventhal says carefully. “But exercise may be one of the only disease-modifying approaches we have.”
“Our auditory cortex synchronizes with the motor cortex,” Leventhal explains — a mechanism particularly relevant in Parkinson’s, where internal rhythm is disrupted by dopamine loss. External rhythm can step in as a kind of substitute metronome. “It creates a roadmap,” Leventhal says. “Someone described it as a red carpet rolling out in front of them.” For people who struggle to initiate movement, that cue can be transformative, enhancing neuroplasticity — the brain’s ability to form new connections.
“Novelty is huge,” Leventhal says. “New patterns, new music, new movement.” But novelty alone isn’t enough. “When something is also meaningful to you — when it connects emotionally, that’s when the brain is really activated.”
Another, more practical advantage: People keep coming back. Some participants have been dancing with Leventhal for over 16 years. People are welcome at all stages of Parkinson’s. Some arrive in a wheelchair, others have recently been diagnosed. “If people can get to class, they stay,” Leventhal says.
That kind of adherence is rare in exercise programs, especially for chronic conditions. The reason, again, circles back to neuroscience. Motivation is tied to dopamine, the very neurotransmitter depleted in Parkinson’s. Apathy is common. Getting on a treadmill can feel like scaling a wall. Dance, by contrast, lowers the barrier.
“The combination of music, social interaction, and movement is highly motivating,” Leventhal says. “Some people come to see their friends and stay for the movement. Some come for the music.”
And one more factor he considers crucial: “We don’t treat people as patients,” he says. “You’re a dancer. You’re learning a craft.”
When we move rhythmically, stress hormones like adrenaline and cortisol decline while the brain’s own reward chemicals — endorphins, dopamine, serotonin — surge, a set of “pleasure cycles” documented by researchers at Aarhus University who studied how music and synchronized movement generate feelings of social bonding and euphoria.
For people living with depression, anxiety or trauma, dance offers something more subtle: a way back into the body. According to a 2024 review, dance can be more effective in alleviating depressive symptoms than any other form of exercise. Where distress constricts expression, dance expands it.
Plenty of workouts happen with headphones and in isolation. Dance, by contrast, almost always involves connecting with others. Social neuroscientists have shown that moving in synchrony with others increases liking, trust, and willingness to help. “We entrain to each other,” Leventhal says. “And that raises empathy, connection.”
For people with Parkinson’s, the stakes are higher than mood or fitness. The disease is the fastest-growing neurodegenerative condition in the world. By the time it is diagnosed, estimates suggest that roughly 70% of dopamine-producing cells are already lost.
Which makes timing critical. “We want people to start earlier,” Leventhal says — not just to maintain function, but to build skills and resilience before symptoms advance.
At the end of Leventhal’s class, the participants play an imaginary volleyball game, batting an invisible ball through the air. “We won, you won, we all won!“ Leventhal cheers, and all arms lift in victory.
To our human eyes, a mouse’s furred face doesn’t betray much emotion. But if you watch the body language of a mouse who’s reunited with one of her sisters after five days in a cage alone, you might suspect you know what she’s feeling.
The formerly isolated mouse chatters in squeaks too high for a human to hear. She follows her sister, crawling beneath the other mouse’s body as if trying to get a hug. She looks like she’s feeling what you or I feel when meeting a long-lost friend or a family member — maybe with more sniffing.
She looks like she’s been lonely.
Loneliness isn’t just for humans, and neither are its harms. Knowable Magazine explored how over the past decade or so, some researchers have come to believe that an animal’s craving for the company of others isn’t just a preference, but a basic, deeply held need. When we don’t socialize enough, we feel the lack like hunger or thirst, they say. When we’ve had our fill of togetherness, we feel satisfied or quenched.
The amount of socializing a creature needs may be particular to that species, and even to that individual. Scientists have found within-species social differences in birds, monkeys, fish and even cockroaches.
Among humans, “you can feel lonely at a party, or you can feel fine alone in your office,” said Kay Tye, a neuroscientist at the Salk Institute for Biological Studies in California. Whatever the ideal degree of togetherness, Tye and others think that an animal’s need to balance time alone and time with others represents a kind of homeostasis: an equilibrium that’s critical for survival. Today, they are on a hunt to find where, in the brain, this equilibrium is controlled — and hoping their work will hold dividends for lonely humans.
A range of socializing
Beavers live with their immediate families. Starlings flock in huge murmurations. Adult male orangutans roam solo until it’s time to find a mate. What determines an animal’s ideal amount of socializing?
Tim Clutton-Brock, an evolutionary biologist retired from the University of Cambridge, says several factors can push species to become more or less social as they evolve. One is the need to keep warm. Another is foraging: Does searching for food in a group make it easier for that animal to eat, or harder? What about predation — is there safety in numbers, or is it better to be alone and inconspicuous? Do females need help from others to raise their young?
“Dealing with the neighbors” is also important, Clutton-Brock said. For example, the meerkats he studies in the Kalahari Desert live in territorial groups, and constant conflict means it’s better to live in packs. A wild meerkat who’s separated from the group is visibly distressed and looks around constantly. “They very clearly get extremely worried,” he said.
Within each species, Clutton-Brock says evolution has probably allowed for a range of personality types around a certain species average. “There are costs to too much anxiety” about being alone, he said, “and costs to too little anxiety.” A species may do best with a mix of social styles.
Whatever an animal’s right amount of social activity, research suggests there can be dire consequences to mental and physical health when it’s not met. People who are socially isolated, or feel lonely, die sooner. Poor social connections are linked to heart disease and stroke. Certain female rats, when housed alone, are more likely to develop cancer.
Tye started investigating loneliness well before the pandemic brought the subject to the forefront. In 2016, she showed that certain neurons in the brain stem — the deepest, oldest part of the brain — are active in male mice who are isolated for a day and then meet another mouse. When scientists inhibited those neurons, the formerly isolated mice were more standoffish; when scientists activated the neurons, the mice were more eager to seek out company.
The researchers realized they might be getting a glimpse, Tye said, of “the cellular substrate of loneliness.”
In 2019, Tye and co-author Gillian Matthews proposed that those brain stem neurons are part of a system of social homeostasis. Like a thermostat, they theorized, a mouse’s brain senses how much company the animal has been getting, and measures that against an ideal. This ideal can also be called a set point. In the human body, for instance, the set point for temperature is around 37 degrees Celsius (98.6 degrees Fahrenheit); when humans deviate from that they’ll shiver or sweat. Likewise, the researchers suggested, the mouse’s brain drives its behaviors to maintain the right balance of social activity.
The scientists hypothesized that other animals, including humans, share this system. Though it’s not easy to test such a thing in people, Tye did team up with a research group at the Massachusetts Institute of Technology for an experiment in which people sat alone in a room for 10 hours.
Afterward, subjects reported craving social interaction. When they viewed pictures of people laughing together, their brains lit up in the same region as the brains of fasting subjects who viewed pictures of food: an area, also within the brain stem, packed with dopamine neurons that are involved in cravings.
For more evidence that this craving is part of a true homeostatic system, Catherine Dulac, a neuroscientist at Harvard University and the Howard Hughes Medical Institute, looked in another part of the brain: the hypothalamus, a deep region just above the brain stem that houses control centers for hunger, thirst and our need for sleep. It calibrates each of these basic needs using a kind of neural thermostat — or, as Dulac likes to call it, a “bean counter.”
In the case of hunger, for example, scientists have found one set of neurons within the hypothalamus that drives appetite and tells an animal to eat. A separate set of neurons drives fullness — what biologists call satiety — and tells the animal to stop eating. Dulac guessed that she’d find a similar system in the hypothalamus for loneliness, comprising two sets of neurons: “one that encodes the need” for company, she said, “and one that encodes the satiety.”
In a study published in 2025, she and her colleagues isolated adult female mice for five days. On days one, three and five, each isolated mouse got to have a 10-minute visit with her sister. Peering inside the heads of the mice undergoing these separations and reunions, the researchers saw just what they were looking for: One cluster of neurons in the hypothalamus started firing when animals were isolated, and turned off when they were reunited. A second cluster of neurons did the opposite.
What’s more, when scientists used a technical trick called optogenetics to artificially activate the separation neurons every time the animals entered a certain chamber, the mice avoided spending time there. That suggested that these brain cells, when activated, give the mice a bad feeling. “It’s unpleasant to be alone, in the same way it has been shown that it’s unpleasant to be hungry,” said Dulac, who co-authored an overview of social interaction as a fundamental need in the 2026 Annual Review of Neuroscience.
But activating the opposite cells — the reunion neurons — led the mice to spend more time in the chamber. These cells are connected to the brain’s dopamine system, which doles out pleasure and rewards.
Aside from making us feel good or bad, Dulac said, the hallmark of a homeostatic system is a “rebound” effect — the greater the deprivation, the more an animal needs to make up for it. When we’re parched, we drink more. And the researchers saw the same thing in their mice: The longer a mouse had been isolated, the more time she spent following, sniffing and squeaking to the other one.
Dulac said that her findings in the hypothalamus and Tye’s in the brain stem probably represent different components of the same system. Other studies have found neurons in still more parts of the brain that may be involved.
Like our appetite for food, the mechanism for social homeostasis may be distributed through many parts of the brain, Tye said. After all, our brain needs to detect the amount of socializing we’re getting, compare it to an ideal, and then drive our behavior so we get more or less company.
The scientists also believe that the circuitry that senses and manages loneliness is likely to be similar in the human and rodent brains. Unlike our more recently evolved cortex, our deep brain regions look much the same as what’s inside a mouse’s head. A lonely human may be feeling the effects of wiring laid down long ago in our evolution.
The importance of touch
After studying female mice, Dulac has now turned to studying male mice, who have competing social motivators because they’re territorial toward other males.
Tye, for her part, has begun to look at females after studying males. So far, she’s observed that they get more and more social over time — unlike the males, which become antisocial after two weeks in isolation and don’t seem happy when reunited with other mice. “It’s like avoidant, territorial, get-off-my-lawn vibes instead of wonderful-to-see-you-again vibes,” Tye explained. The scientists don’t yet understand this fundamental sex difference.
Intriguingly, researchers have also observed an antisocial effect in human prisoners subjected to long-term solitary confinement. In addition to other psychological harms, prisoners may stop craving social contact and start to fear it.
Besides attempting to understand the differences between chronic and short-term isolation, researchers are also trying to learn how creatures use their senses to gauge how much company they have.
In Dulac’s experiments, vision didn’t seem to be necessary: Blind mice reacted to separation similarly to sighted mice. Nor did scent or sounds hold the answer: When mice were physically separated by a perforated divider within the same cage — so they could still hear and smell their companions — they reacted as if they’d been fully isolated.
The only sense that seemed to matter was touch: The brush of another mouse’s body told mice they had a friend nearby.
When the researchers lined a tube with soft cloth for mice to walk through, they saw that isolated animals preferred the soft tunnel to a hard one. Like a weighted blanket for humans, perhaps, the touch of the furry walls made the lonely mice feel a little better.
Ishmail Abdus-Saboor, a neurobiologist at Columbia University’s Zuckerman Institute who studies touch and was a co-author on Dulac’s study, said the result didn’t surprise him. “It is consistent with touch being perhaps one of the most essential sensations for well-being,” he explained.
The human sense of touch is not just one thing. Bodies have different pathways for processing different sensations, such as pain or itch — or social touches. Humans have specific neurons in the hairy parts of our skin, for example, that are activated by slow stroking. (Mice have related neurons.) And deep pressure, akin to a hug or a massage, activates a similar brain region to stroking touch.
Abdus-Saboor is now working with naked mole rats in his lab. These quirky, colony-living rodents are both the world’s most social mammals and conspicuously cuddly. He hopes studying them will provide more answers about the connection between touch and sociality. He even thinks they might be better models than mice for social touch in humans, because their nearly hairless skin is more similar to ours than a mouse’s.
These social touch neurons may carry signals from an animal’s skin to its brain that tell its bean counter it’s not alone, making the animal feel better. “If we can hijack this pathway, can this be used as a therapeutic to promote health and well-being? I think so,” said Abdus-Saboor, who wrote an overview of social touch research in the 2026 Annual Review of Neuroscience.
Even before scientists use this research to develop new treatments, Dulac says it highlights the danger of solitary confinement in prisons. “When individuals are left alone, their brain is just sending this danger signal: ‘You should not stay alone,’” she said.
Tye imagines that if scientists better understood the brain’s social bean counter, they could one day find a way to lessen the health effects of isolation. For now, she and her co-authors suggest that spending time in a variety of social settings is the best way to buffer yourself against discomfort.
Before COVID-19, Tye recalls, she was always with other people. Then, “during the pandemic, I was alone a lot. And it was really stressful for me,” she said. She thinks that giving ourselves regular alone time, as well as time in small and large groups, can make us more tolerant of changes.
Because we’re not rodents, we might be able to get our social needs met — at least partially — in ways that they can’t. We can connect with a loved one through a call or text. Still, Tye says, touch seems to be especially vital.
Abdus-Saboor, who is married with two children, says he’s “very intentional” about touching his family: a supportive tap, a back rub. His kids are old enough to walk to school on their own, but he makes sure to check in before they go.
“It’s like, ‘Let me get that hug before you leave,’” he said.
A new remarkable finding could help the fight against cancer. Researchers in Japan have found specialized bacteria that not only wiped out cancerous tumors in mice, but did so in one single treatment. The kicker is that this tumor-busting bacteria was found within the guts of Japanese tree frogs.
Professor Eijiro Miyako and his team at Japan’s Advanced Institute of Science and Technology (JAIST) were looking for direct methods to use natural bacteria strains to attack cancer cells. They collected and isolated 45 bacterial strains from the intestines of Japanese tree frogs, fire belly newts, and grass lizards. They then proceeded to test each one on cancerous tumors found in lab mice.
The research
After experimentation and systematic screening of the 45 bacterial strains, nine of them showed anti-tumor effects. However, the E. americana strain found in Japanese tree frogs showed the highest potential. It didn’t just kill the cancer cells in the mice, but engaged the immune system within the mice to “comprehensive tumor destruction.”
Within a single dose of E. americana, mice with colorectal cancer had a 100% response rate that led to complete elimination of all tumors. This breakthrough surpasses the response of current standard therapies to treat this type of cancer, including chemotherapy agents.
Is this bacteria safe?
The E. americana strain also showed an excellent safety profile. Aside from mild inflammation responses that usually normalized within 72 hours, there appears to be little negative effect. There was no bacterial colonization detected in the organs of the mice. There was also no chronic toxicity during 60 days of extended observation. While more and extensive testing is needed to confirm, this colorectal cancer treatment appears to be effective, quick-acting, and safe.
Great news during a trying time regarding colorectal cancer
This news comes at a time when there has been a rise of colorectal cancer rates among younger people. In fact, it’s the most common cancer-related death among people under 50 years old, and second most common cancer death overall. This tree frog bacteria could significantly impact those statistics. If the potential rings true, a single dose could eliminate all of the tumors without the need of surgery.
The researchers intend on testing this bacteria on other forms of cancerous tumors. They also want to test other, safer administration methods to see if it can be even more effective. While it can already help eliminate colorectal cancer tumors, testing might show it to be an effective overall cancer treatment.
Reptile and amphibian research helps human medicine
While humans are biologically different from reptiles in numerous ways, many medicines have been derived from them. GLP-1 drugs such as Wegovy and Ozempic were created after discovering that gila monster venom reduced blood sugar. Similarly, snake venom has shown signs of being effective in reducing pain and inflammation as an arthritis treatment. It’s not just gut bacteria, but venom from all sorts of reptiles and amphibians is being tested as cancer treatments, too.
Whether you’re a fan or not, reptiles and amphibians could hold the potential to save thousands of human lives.
