Title: A Scientific Explanation of How Marijuana Causes the Munchies  | Science   | Smithsonian Magazine
Headings: A Scientific Explanation of How Marijuana Causes the Munchies
A Scientific Explanation of How Marijuana Causes the Munchies
THC appears to increase our sensitivity to scents and flavors by using naturally occurring neural networks to convince the brain that it’s starving
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Content: Our brains typically produce their own chemicals (called cannabinoids) that fit into these same receptors, so by mimicking their activity, THC can artificially alter the same factors in dramatic ways. The scientists began by exposing mice ( increasingly used in neuroscientific research because of the surprising amount of cognitive similarities they share with humans) to banana and almond oils as a test of sensitivity to scent. When they did so, the mice sniffed the oils extensively at first, then stopped showing interest in them, a well-known phenomenon called olfactory habituation. Mice that were dosed with THC, however, kept on sniffing, demonstrating an enhanced sensitivity to the scents. These THC-dosed mice also ate much more chow when given the chance, showing an increased appetite. The researchers also genetically engineered some mice to lack a type of cannabinoid receptor in their olfactory bulbs and subjected them to the same experiment. They found that even if these mice were given THC, it had no effect: They still habituated to the scent, showing that the drug's scent-enhancing powers involved activity in this region of the brain. In addition, these mice did not demonstrate an increased appetite when given the drug, showing that the "munchies" effect was dependent on olfactory lobe activity as well. The upshot of all this: