Puff Puff Pass: The Tale of THC

Why do people smoke pot recreationally? The most obvious answer is to get high.

But what does it mean to be high? Being high on marijuana has been described as feeling “…euphoria, relaxation and changes in perception,” often accompanied by an inexplicable fascination for colorful images and psychedelic fractals.

We do it because it’s fun, but  have you ever considered what “being high” means on a physical/chemical scale? What is happening to our brains when we smoke the devil’s lettuce? Let’s take a journey into the body—and follow the ever famous THC molecule.

We start our journey on the fruit of the cannabis plant, the part that we smoke. Tetrahydrocannabinolic acid  (THCA) exists both inside the plant, as well as on the surface in crystal structures known as trichomes. You may think this is the molecule that gets us high; you would be mistaken. THCA is an inactive form of the molecule, it does nothing for us psychotropically speaking.

The active form of the molecule has a carbon dioxide (CO2) group removed. Worry not, there are a few ways to activate it. Certain animals, such as dogs, can use a molecular machine, known as an enzyme, to bind with, and activate THCA. However, humans do not contain said enzymes. THCA can also be activated via heat, thus the reason we smoke and/or cook weed!

THCA spontaneously converts to Δ9-tetrahydrocannabinol (THC) when the temperature around it exceeds 240°F, luckily it vaporizes at 315° F. It is then inhaled down the throat, and into our lungs.

Though THC can be absorbed by any mucus membrane (i.e. slimy tissue), most of it is absorbed into our blood via the alveoli, broccoli like structures in our lungs. Here, THC is circulated throughout the entire body, via the heart, and binds to cannabinoid receptors all throughout the body. Despite THC’s promiscuity (it goes everywhere!), we are focused on the best organ of all, the brain.

In order for THC to enter the brain, it has to pass through the Blood-Brain Barrier (BBB), which essentially is a fairly impenetrable wall that keeps most things out of the brain, kind of like heavy duty border patrol—though some molecules like THC can sneak past!

Now, we are in the brain. Due to the vast complexity of the human brain, THC has many targets and activates/deactivates many pathways. The primary path associated with THC is its positive effect on dopamine, the “feel good” neurotransmitter.

After THC enters the brain, it finds cannabinoid receptor 1 (CB1). You can think of CB1 as a guard to a gate. When THC interacts with CB1, the guard opens the gate allowing calcium out of the neuron. This stops the neuron from working. Without the calcium present in the neuron, it cannot release its inhibitory molecule. Think about inhibitory molecules as a dam on a river; if the dam is present, water will flow much less than if it were absent. In our scenario, the dam is the inhibitory molecule, and the flow of water is the movement of dopamine throughout the brain.  

With all of this excess dopamine in the brain, we have many senses heightened and experience the “high.” Obviously, this effect will not last forever. THC does not permanently bind to CB1; it attaches and releases at a certain rate.

While THC is not bound, it has a chance of being swept away by our bodies regulatory systems and eventually exits the body. With the THC cleaned out, our brains resume normal function.

When we are stoned we let our minds wander. We find ourselves entranced by the world around us. Yet the underpinnings of the “high” often escape our thoughts.

from
http://hightimes.com/medicinal/puff-puff-pass-the-tale-of-thc/