In the study, German and Israeli scientists tested the memory and cognition of two-month-old “young” mice, 12-month-old “mature” mice,’ and 18-month-old “old” mice after giving them low doses of THC, the main psychoactive component of marijuana, over a month-long period, reports PRI.
The study was published in the scientific journal Nature Medicine.
Marijuana Improves Performance In Mature Mice
The researchers tested the mice’s recognition of “familiar objects” and had the animals go through “a water maze in known and new configurations.” The group of elderly mice displayed no negative side effects from the THC while the younger mice lost cognitive skills.
Interestingly enough, the young mice after being given THC performed worse on cognitive tests. This is consistent with studies of human cannabis users under age 16, said Harvard psychiatrist Staci Gruber, who wasn’t involved in the study. “That’s because the brain is still absolutely, positively immature,” Gruber said.But the mature and old mice given THC performed noticeably better on cognitive and memory tests than their un-stoned counterparts. Their brains also underwent positive physical changes in synaptic connections and gene expression, making them appear more like the brains of younger mice.
“So, a little bit of THC to the young mice made them perform significantly worse,” Gruber said. “That is, they looked like old mice who hadn’t been treated, while the mature and old mice who were treated with THC looked like the young, untreated mice.”
Brain Plasticity ChangeCo-lead authors on the study, Onder Albayram, a research fellow at Harvard Medical School and Andreas Zimmer, director of the Institute of Molecular Psychiatry at the University of Bonn, worked with an international team of researchers in Germany and Israel, reports Peter Hess at Inverse.
“The young brain has lots of endocannabinoids, and an old brain has significantly less,” Albayram told Inverse. “That’s why when you give THC to a young brain, which can access lots of endocannabinoids, this confuses the brain. But when you give THC to old brains, they have less endocannabinoid binding affinity, so the brain experiences a plasticity change to adapt to high THC.”
“Humans and mice also have the same proteins and biological systems,” Albayram said. “Their brains use cannabinoids for memory consolidation. We will find a way to move to human studies.”
“We’ll have to see how that plays out in humans, but it’s certainly promising,” said Gruber, who directs programs researching cannabis and the brain for McLean Hospital, which is affiliated with Harvard University.
Gruber said her own current research indicates there may be a cognitive improvement after just three months of cannabis use. “We follow them for two years, but the first set of data comes after only three months, they look like they’re performing better,” she said.
Human Trials NeededWe need to replicate the mouse study with human clinical trials, according to Gruber. In the U.S., such research would be difficult, because of marijuana’s federal Schedule I classification and the resulting limitations on cannabis research.
“Currently, there’s only really once source from which you can obtain product to administer to human subjects,” Gruber said. “And we certainly wouldn’t ever be in a position to be able to administer products like that to, let’s say, our youngest consumers, our adolescents. That’s probably not going to happen, for all sorts of ethical reasons.”
But continuing to study the effects of THC in improving adult cognition could shift perceptions of medical marijuana, and lead to new uses for it.
“Typically, what we see in the THC-related literature, or studies of recreational marijuana, really have been reports that THC is detrimental to the brain,” Gruber said. “But again, mostly those studies focus on individuals who are young.
“We don’t necessarily know about the impact on older folks,” she said. “And when you’re beyond the level, or beyond the period of vulnerability, could it potentially be facilitative? We don’t know.”
Given the promising findings, researchers said they plan to conduct a similar experiment on older “human brains” via a clinic trial sometime this year, reports Barry Bard at Marijuana.com. Cannabis could very well help keep older brains sharper for a longer period of time, and one of the study’s co-authors, Andras Bilkei-Gorzo, said just that:
“If we can rejuvenate the brain so that everybody gets five to 10 more years without needing extra care then that is more than we could have imagined.”
Endocannabinoid System Is KeyThe study builds from a theory that slowdowns in the brain’s endocannabinoid system — home of the receptors to which THC binds — is related to cognitive aging and decline, reports David DiSalvo at Forbes. As we grow older, the ECS slows down, and our brains produce fewer of the naturally occurring endocannabinoids.
While all the outcomes from this slowdown aren’t completely understood, there’s enough evidence from animal studies to suggest it’s tied to memory loss and decreased learning ability.
“With increasing age, the quantity of the cannabinoids naturally formed in the brain reduces,” said Professor Andreas Zimmer, one of the new study’s authors. “When the activity of the cannabinoid system declines, we find rapid aging in the brain.”Recharging the endocannabinoid system with plant-based cannabinoids could reverse or at least reduce the cognitive slowdown. That’s why the researchers included old mice in the study — and the results were striking.
When scientists studied the brain tissue and gene activity of the older mice after a low-dose THC treatment, they found that the genetic signature no longer looked that that of old mice, but instead resembled that of very young mice. Incredibly, they also found increased nerve connections in the brain tissue, which correlates with learning and quick thinking.
“It looked as though the THC treatment turned back the molecular clock,” an amazed Professor Zimmer said.
“Together, these results reveal a profound, long-lasting improvement of cognitive performance resulting from a low dose of THC treatment in mature and old animals,” the scientists wrote.
Unlocking the Incredible Potential of Cannabis
The current federal prohibition on marijuana is blocking medical experts from effectively studying the uses of cannabis in treating Alzheimer’s disease and other effects of aging on the brain.
The designation of cannabis as a Schedule I controlled substance alongside heroin and other deadly narcotics means that the U.S. government officially considers weed more dangerous than both methamphetamine and cocaine, which are Schedule II drugs.
Scientists at the Salk Institute for Biological Studies in California are finding very promising early success in looking at cannabis extracts for treating Alzheimer’s, reports the Daily Caller. But their reliance on federal grant money is already creating problems.
When will the federal government finally come to its senses and put medical science and human quality of life above outdated politics and 20th century superstitions? Is that just too much to expect from the science-denying, scandal-riddled, low-IQ Trump Administration? Stay tuned.