Hey, this is Julie Douglas from the podcast The Stuff of Life here to tell you that super producer Noel Brown and I are cooking up season two for an August release. So if you haven't already checked out season one of the Stuff of Life, there's a big bowl of ten episodes ready for you to dig into on iTunes or wherever you get your delicious podcast take out from. In the meantime, apply sunscreened liberally and we'll see you in August. Welcome to brain Stuff from How Stuff Works. Hey,
brain Stuff, this is Christian Seger. So here in the United States, marijuana is most commonly used as an illicit drug. Our society thinks of stereotypical users as being you know, forgetful and absent minded. And this is because the main psychoactive ingredient in marijuana impairs our memory. It's called tetro hydro cannabinal or for the sake of you know, brevity, th HC. Th HC alters how information is processed in the hippocampus. This is the area of the brain that
is responsible for memory formation. However, you consume marijuana, THHC enters your brain by latching onto a protein called cannabinoid receptor type one, or c B one for short. There are c B one sprinkled throughout the brain. There in your cortex, basil, ganglia, the hypothalamus, and the hippocampus where we form our memories. See where I'm going here for a short term memory. Forty years worth of different studies show that th HC disrupts our short term memory, making
it hard to form new memories when you're high. This also makes it really difficult to remember what happened when you were high, even after the th HC wears off, and larger doses of th HC have even more of an effect on memory. Frequent users are more tolerant to the th HC, however, and its effects including memory loss. But what about recalling your existing memories. Th HC does not actually affect that, nor does it lead to memory
loss or dementia. Therefore, users can remember things they already know, like their name or where they live. And Our bodies have a biological system made of natural marijuana like compounds. This is called the endocannabinoid system. It regulates our memory formation, functioning as a filter so we're not overloaded with information. The system is involved in the extinction of our negative
memories as well. That's what they call it extinction. It can influence pain, memory, mood, and even appetite, and researchers hope that by using THHC they can help people forget bad memories such as post traumatic stress disorder. So studies do show that as people age, they lose neurons in
the hippocampus, and chronic THC use can hasten this loss. Also, a study out of Northwestern University published in March of fifteen showed that teens who smoked daily for three or more years have been found to have an abnormally shaped hippocampus. They also performed poorly on long term memory tests, eighteen percent worse than those who didn't use marijuana. The deformation of the hippocampus is thought to be connected to this
poor memory. Subjects in this study took a narrative memory test where they listened to a series of stories for one minute twenty to thirty minutes later, they were asked to recall as much from the stories as they could, and this assessed their ability to encode, store, and recall details from their stories. The longer the individuals used marijuana chronically, the more abnormal their hippocampus was shaped. This probably damages its neurons and its axons, as well as supportive environments.
The abnormalities didn't seem to go away either, even when observed in individuals in their early twenties who had stopped using marijuana for over two years now. It's important to note that drawing definitive conclusions about marijuana's long term effects is difficult because steady participants often use multiple substances. Rats exposed to th HC before they're born, after birth, and during rat adolescence show problems with learning and memory tasks
later in their lives. A rats hippocampus changes as well when it's exposed to th HC, and imaging in human adolescence shows that regular users display impaired neural connectivity. This affects memory, learning, and impulse control. The endocannabinoid system is important to the formation of our synapses during early brain development and refining them during adolescence, so it's possible that
marijuana use is affecting this development. If you want to learn more about marijuana, memory, and medical health, I recommend that you go check out my other podcasts stuff to blow your mind. We just recently did two deep dive episodes into marijuana. Check it out. Check out the brain Stuff channel on YouTube, and for more on this and thousands of other topics, visit how stuff works dot com