Pot’s Paradoxical ‘Munchies’

February 19, 2015

solar-flare-tessa-hunt-woodlandGlaringly-bright and warm this mid-afternoon on California’s north coast — according to the NWS, we’re supposed to be about 54 degrees right now, but it sure feels a bit more fervent.

Dude, bright as the sunshine, we might need some groceries, as neatest-interesting news item I’d seen today was this report from NPR on why marijuana produces the famous/infamous, “munchies” — and it boils down to biological science: ‘At the same time, the cannabinoids activate a receptor inside the POMC neuron that causes the cell to switch from making a chemical signal telling the brain you’re full to making endorphins, a neurotransmitter that’s known to increase appetite.’

Literally blinded-sided into eating five bowels of Raisin Bran, and then, a blackberry muffin.

(Illustration: Tessa Hunt-Woodland‘s ‘Solar Flare,’ found here).

The nutshell from the new study on pot’s food-intake effect, and further from NPR, with Tamas Horvath, a neuroscientist at the Yale School of Medicine:

In the past, when neuroscientists shut down POMC neurons in mice, all the mice became morbidly obese.
Horvath figured that in order for the drug in marijuana — compounds called cannabinoids — to spawn that undeniable impulse to feed, it would have to bind the activity of these neurons and make them fire less.
Paradoxically, Horvath says, “We found the exact opposite.”

These two effects combined create a kind of runaway hungry effect.
“Even if you just had dinner and you smoke the pot, all of a sudden these neurons that told you to stop eating become the drivers of hunger,” Horvath says.
It’s a bit like slamming down on the brakes and finding weed has turned it into another gas pedal.

One caveat is that the study — which appears online in the journal Nature — was done on mouse brains, not human ones.
But Horvath says the hypothalamus is such an ancient part of the brain, something that evolved before mammals, that he’d “bet his life” the way these neural circuits work in mice is the same in humans.
Barson says that until you do the experiment with humans, “you can’t know for sure, but it’s reasonable to conclude that it’s the same thing.”
The study is not, however, the final missing piece of the munchies mystery.
A lot of other neural processes get layered on top of what goes inside the hypothalamus, and cannabinoids affect those other parts of the brain as well.
Last year, researchers found that cannabinoids lit up the brain’s olfactory center, making mice more sensitive to smells.
Before that, other researchers discovered cannabinoids were increasing levels of dopamine in the brain; that’s the swoon that comes with eating tasty things.

Analogous to that is a piece of cheese cake awaiting in my fridge…

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