If recent laws legalizing marijuana in more U.S. states also boost sales of potato chips and brownies, scientists will know why: A study in mice published on Wednesday found, unexpectedly, that the active ingredients in pot essentially make appetite-curbing regions of the brain reverse functions.
When that happens, neurons that ordinarily transmit a signal that means, “you’re full, stop eating,” instead give the brain the munchies, neurobiologists reported in the journal Nature.
The fact that smoking marijuana makes users crave salty, crunchy or sweet snacks has long been enshrined in popular lore and comedy. But how that happens has been a scientific enigma.
One idea had involved heightened sensory perception. A 2014 study by neuroscientists in Europe, for instance, found that the active ingredients in marijuana, cannabinoids, affect the olfactory center in the brains of mice. As a result, the animals better smell food, which can stimulate appetite.
But that didn’t explain the marijuana-fueled appeal of foods without much aroma.
In their study, scientists led by Tamas Horvath of Yale University focused on molecules called receptors that cannabinoids bind to and activate in the brains of both mice and men. They expected to find that when cannabinoids did so, the receptors sent out a signal quieting nearby neurons that suppress appetite. That could lead to the munchies.
To their surprise, Horvath said, they found that activating the cannabinoid receptors in mice’s brains instead increased, not decreased, the activity of appetite-suppressing neurons.
The reason that did not suppress appetite was that the neurons, instead of emitting their usual appetite-killing neurochemicals, emitted completely different ones. Called endorphins, they traveled to the brain’s appetite-control region, the hypothalamus, stimulating the mice’s desire to eat.
“Neurons that normally shut down eating instead promoted it, even when the mice were full,” Horvath said in an interview. “Marijuana fools the brain’s feeding system.”
It does not fool the brain into eating just anything, however. Smoking marijuana rarely leads to a craving for broccoli. Instead, he said, the brain mechanisms create a desire for calorie-dense foods like salty, fatty chips and rich sweets.
There are likely additional brain pathways by which marijuana causes the munchies, which could be tapped for one of the drug’s medical uses: increasing appetite in cancer patients and others who have lost the desire to eat.
(Reporting by Sharon Begley; Editing by Cynthia Osterman)
High school wrestling coach posted photo that mocked George Floyd’s death — but insists ‘I’m not a racist’
A high school wrestling coach in the town of Spanaway, Washington drew criticism this week after he wrote a Facebook post that mocked the death of George Floyd and defended the police officers involved in the tragedy.
Local news station KOMO reports that wrestling coach Dave Hollenbeck this week posted a photo of himself smiling and giving a thumbs-up signal while another person put their knee on the back of his neck -- a clear reference to the video showing a police officer with his knee on George Floyd's neck shortly before he died.
Central Park incident just one more example of white women using their status to terrorize black men: NYT’s Charles Blow
Amy Cooper is just the latest example of white women using their privilege and femininity to terrorize black men, according to a new column from Charles Blow.
The New York Times columnist explains that a video recording of an incident involving Cooper, an investment manager, and Christian Cooper, a science editor, has a long and shameful historical precedent.
"This racial street theater against black people is an endemic, primal feature of the Republic," Blow write. "Specifically, I am enraged by white women weaponizing racial anxiety, using their white femininity to activate systems of white terror against black men. This has long been a power white women realized they had and that they exerted."
New Zealand epidemiologist: ‘We look at Trump’s behavior and we’re horrified’
To learn how New Zealand has largely eliminated COVID-19, we continue our extended interview with Michael Baker, an epidemiologist who is a member of the New Zealand Ministry of Health’s Technical Advisory Group and advising the government on its response to the COVID-19 pandemic. He describes how the country’s response compares to the government actions in the United States and worldwide.
This is a rush transcript. Copy may not be in its final form.
AMY GOODMAN: This is Democracy Now!, democracynow.org, The Quarantine Report. I’m Amy Goodman, with Juan González, as we bring you Part 2 of our discussion of New Zealand.