PULLMAN, Wash. — A long-standing mystery has finally been solved: why do we get the munchies after smoking marijuana? Washington State University (WSU) scientists say a mechanism in the brain explains why consuming cannabis leads to increased appetite. They’re now hopeful this discovery leads to new treatments for eating disorders.
Researchers conducted a series of animal studies to investigate this phenomenon. They exposed mice to vaporized cannabis sativa and then used a technique known as calcium imaging to monitor the brain’s response. This technology, akin to a brain MRI, revealed that cannabis activated specific cells in the hypothalamus when the mice anticipated and consumed palatable food. These cells remained inactive in mice that weren’t exposed to cannabis.
“When the mice are given cannabis, neurons come on that typically are not active,” says study corresponding author Jon Davis, an assistant professor of neuroscience at WSU, in a university release. “There is something important happening in the hypothalamus after vapor cannabis.”
💡What Is Marijuana?
- It comes from the Cannabis sativa plant and contains THC
- THC is a compound that causes a feeling of “high” by affecting brain activity
- Its health effects can be positive (pain relief, nausea reduction) and negative (impaired cognition, addiction risk)
While previously used to study brain reactions to food, this was the first time researchers have applied calcium imaging to understand the brain’s response to cannabis exposure.
Researchers also pinpointed a key player in this process: the cannabinoid-1 receptor, a well-known target of cannabis. This receptor influences the activity of Agouti Related Protein neurons, which are crucial for feeding behavior in the hypothalamus. Using a technique called chemogenetics, which acts like a molecular switch, the team was able to selectively activate these neurons. They found that when these neurons were deactivated, cannabis lost its appetite-stimulating effect.
“We now know one of the ways that the brain responds to recreational-type cannabis to promote appetite,” states Davis.
This research builds on earlier studies from Davis’ lab, which were among the first to use vaporized cannabis plant matter instead of injected THC in animal studies. This approach more closely resembles human cannabis use. Earlier, the lab identified genetic changes in the hypothalamus due to cannabis, prompting the focus on this brain region in the current study.
Funding for this research came from various sources, including the Alcohol and Drug Abuse Research Program, the National Institute on Alcohol Abuse and Alcoholism, the U.S. Department of Agriculture, and state funds from Washington Initiative Measure No. 171.
The study is published in the journal Scientific Reports.
6 Reasons People Use Cannabis
Cannabis has been a subject of interest in the medical community for its potential health benefits. While it’s commonly associated with its psychoactive properties, there’s more to this plant than meets the eye. Here are six medical-based uses for the drug:
Pain Management – One of the most well-recognized benefits of cannabis is its ability to manage pain. Compounds in cannabis, namely CBD (cannabidiol) and THC (tetrahydrocannabinol), interact with the body’s pain receptors, potentially providing relief for chronic pain, arthritis, and nerve pain.
Mental Health and Mood Disorders – Cannabis has shown promise in addressing various mental health conditions. It’s been used to alleviate symptoms of anxiety and depression, and has shown potential in PTSD treatment, helping to reduce flashbacks and nightmares.
Appetite Stimulation – In individuals facing appetite loss, such as cancer patients undergoing chemotherapy, cannabis can act as an appetite stimulant. This can be crucial in ensuring adequate nutrition during treatment.
Sleep Aid – Cannabis, particularly strains rich in CBD, may improve sleep quality. It can help with falling asleep faster and potentially improve sleep disorders like insomnia.
Neurological and Cognitive Disorders – There’s emerging evidence that cannabis can benefit certain neurological and cognitive disorders. For instance, CBD has been approved for treating two severe forms of epilepsy. There’s also ongoing research into its effects on other conditions like Alzheimer’s and multiple sclerosis.
Heart Health – Initial studies suggest that CBD may benefit heart health by lowering high blood pressure, which is linked to heart disease, stroke, and metabolic syndrome.
While cannabis presents numerous potential health benefits, it’s crucial to approach its use carefully. It’s not suitable for everyone, and the psychoactive effects of THC can pose risks, especially in high doses or in individuals with certain mental health disorders.
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