Name: How Does a Brain on THC Compare to a Brain on CBD?
Uploaded: undefined
Duration: undefined

Nova

Koch Foundation

NOVA Science Trust Logo

A University of Utah study is analyzing the effects that two cannabinoids—psychoactive THC and non-intoxicating CBD—may have on the brain.

Scientists are working to understand the true effects of cannabis on the brain.

A University of Utah study is analyzing the effects that two cannabinoids—psychoactive THC and non-intoxicating CBD—may have on the brain.

How Does a Brain on THC Compare to a Brain on CBD?

Scientists are working to understand the true effects of cannabis on the brain.

Body & Brain

How Does a Brain on THC Compare to a Brain on CBD?Published: October 27, 2021Narrator: At the University of Utah, in Salt Lake City, a study is looking at the effects of the two key cannabinoids in cannabis: THC, the psychoactive cannabinoid that makes users feel high, and CBD, a nonintoxicating cannabinoid.Over eight visits, researchers get consent from healthy volunteers and then give them a placebo, 600 mg of CBD, 10 milligrams of THC, or both CBD and THC. The study is double-blinded, meaning neither the researchers nor the participants know for sure what the participants are taking. However, some participants could feel some effects and assume something about what they were given.Once the drugs take effect, the volunteers undergo imaging and a battery of cognitive tests to analyze their brain activity. The goal is to understand how a brain on THC compares to one on CBD, and to one that has received neither, or both.Jeff Anderson: There's a brain network that's responsible for reflections about our lives, our days. That voice that's always there in our head as we talk to ourselves. We see under the presence of THC, that process slows down—where the brain doesn't change from one idea or one state or one thought as fast as it would under normal circumstances. And that probably has a big effect on brain function. It probably means that the brain is quieter.Narrator: According to the fMRI data in the Utah study, under the influence of THC, some connections between different brain regions are more active, but others grow weaker and take longer as the brain works harder to perform a task.Jeff Anderson: On the whole, people under the influence of THC are not able to perform as well on cognitive tests. They have slowed reaction times. They have decreased executive function. At the same time, the usual brain networks with their rigid boundaries loosen and become more flexible. You can draw in information from other regions of the brain that have different information available. That’s what creativity is.Narrator: But what about a brain on CBD? How does its activity compare?Jeff Anderson: We haven't seen convincing data yet from our experiments that there is any effect that we can measure in the brain with CBD.Narrator: Though the Utah team didn’t see any significant visible effects of CBD on participants’ fMRI data or when compared to the placebo, other researchers continue to look for potential impacts of CBD on the brain— including studying how it interacts with cells in the lab.Alysson Muotri at the University of California San Diego is testing the effects of CBD on human brain cell networks in vitro. Muotri started with human skin cells, converting them back into master builder cells—that is, stem cells—and then persuading them to develop as brain cells do, forming networks of neurons.Alysson Muotri: These brain cells, they will actually self-arrange and form what we call a brain organoid, and as they mature, over time, they start to become more and more electrically active.Narrator: That activity is captured by electrodes placed beneath the cluster of brain cells. When their neurons fire, they create electrical signaling comparable to a developing brain. Next, the brain cells are treated with different doses of CBD to see if the drug has any impact.Alysson Muotri: One of the biggest surprises that we see is that by adding CBD in the culture, we actually silence or quiet the activity of these brain cells, over time. This is not permanent. We can wash it out, CBD, from the system, and we see that the brain is able to restore electrical activity.Narrator: Some clinical trials have demonstrated beneficial effects of CBD, showing that it can reduce seizures for some people suffering from certain forms of epilepsy. But many more clinical trials are currently underway trying to determine CBD’s effects on a range of conditions, including anxiety, PTSD, autism, and chronic pain.As the cannabis industry continues to grow and market CBD and THC as medically beneficial, scientists are working to understand the true effects of these cannabinoids on the brain.

United States

Northern Mariana Islands

Puerto Rico

American Samoa

Guam

U.S. Virgin Islands

U.S. Minor Outlying Islands

US & Territories

NOVA investigates the story of cannabis from the criminalization that has disproportionately harmed communities of color to the latest medical understanding of the plant. What risks does cannabis pose to the developing brain? How much do we know about its potential medical benefits? As cannabis becomes socially accepted, scientists are exploring its long-term health consequences. (Premiered September 29, 2021)Check out a previously recorded panel discussion and audience Q&amp;A featuring experts and producers from "The Cannabis Question" <a href="https://youtu.be/nSTT5RZ_hxA">here</a>.

As state-legalized cannabis spreads, NOVA explores its little-known risks and benefits.

The Cannabis Question

A 2006 composite image from NASA's Hubble Space Telescope and Spitzer Telescope shows the chaos of baby stars in the Orion nebula some 1,500 light-years away. Image Credit: NASA/JPL-Caltech/STScI

With the upcoming launch of the James Webb Space Telescope, the Hubble era is gradually drawing to a close. Here are some highlights from the countless wonders Hubble has shown us during its 31 years in space.

10 spectacular Hubble Space Telescope images

A statue of Zheng He at the Sam Poo Kong Temple in Java, Indonesia. Image Credit: Budianto Santosa, Shutterstock

In the 1400s, Zheng He sailed thousands of miles around Asia and Africa in ships the size of soccer fields, spreading Chinese innovations like compasses and gunpowder in the process.

How Does a Brain on THC Compare to a Brain on CBD?

Support Provided By

Explore More

How Cannabis Affects Teens' Brains

The Cannabis Question

CBD Helps Anxiety Patients in a Clinical Trial

Transcript

Sources

Support Provided By

Explore More

How Cannabis Affects Teens' Brains

The Cannabis Question

CBD Helps Anxiety Patients in a Clinical Trial