Effects of Marijuana on the Brain

One region of the brain that contains a lot of THC receptors is the hippocampus, which usually helps with memory. When THC attaches to receptors in the hippocampus, it interferes with memory. Researchers have also shown that heavy use of marijuana by young people can actually cause IQ to go down—and this change in IQ can last a long time and may even be permanent! This means that someone who uses marijuana may not do as well in school and may have trouble remembering things like their friend’s phone number. Maybe you’ve heard that marijuana can cause a range of emotions from uncontrollable laughter to paranoia. That’s because THC also influences emotions, probably by acting on a region of the brain called the limbic system. And don’t forget this: THC can make something as simple as driving a car really dangerous.


Some chemicals in the marijuana plant might be useful in the world of medicine— like preventing nausea and blocking pain, and possibly treating other problems and diseases. The trick is for scientists to get these results without the harmful effects. Researchers are studying these chemicals— so that they can develop medications that are chemically similar to THC but don’t negatively affect the brain.

The Brain’s Response to Marijuana - You may have heard it called weed, pot, grass, ganja or skunk, but marijuana by any other name is still a drug that affects the brain. Did you know marijuana can have different effects on different people? For example, it can cause some people to lose focus on things around them. It makes others more aware of their senses– like sight, sound, smell, and taste, and it has still different effects on other people.

Marijuana is the dried leaves and flowers of the hemp plant (Cannabis sativa). Like all plants it’s sensitive to the environment where it grows. Different weather and soil conditions can change the amounts of the chemicals inside the plant. That means marijuana grown in a place like Hawaii might be chemically different than marijuana from Mexico, or vice-versa.

When someone uses marijuana, these chemicals travel through the bloodstream and quickly attach to special places on the brain’s nerve cells. These places are called receptors, because they receive information from other nerve cells. Chemicals carry this information, which changes the nerve cell receiving it. One chemical in marijuana that has a big impact on the brain is called THC— tetrahydrocannabinol. (Whew! Try saying that 10 times fast.) Scientists have found that some areas of the brain have a lot of THC receptors, while others have very few or none. These clues are helping researchers figure out exactly how THC works in the brain.


Adapted from National Institute on Drug Abuse (NIDA DrugPubs)

Anxiety avoidance and the brain

The excellent Anxiety series from The New York Times recently included a piece called "For the Anxious, Avoidance Can Have an Upside" by Joseph LeDoux, a neuroscientist I've referred to a number of times in the past here on PANIC! The article posits that avoidance isn't always maladaptive:

...people with social anxiety often cope with their problem by avoiding social situations altogether.  This is not practical or beneficial.  But neither is forcing oneself to show up at parties and just try to ride out the anxiety.  A more effective treatment approach might be to combine anxiety-producing exposure with strategies that allow one to gain control over the anxiety trigger cues.

Michael Rogan, who was a researcher in my lab when the active coping work was first being done, currently treats people with social anxiety. He suggests to his clients with social anxiety that they should, when at a party, identify strategies for temporary escape and avoidance (go into the bathroom, step outside to make a call), and also use previously learned relaxation techniques (controlled breathing, imagery, mindfulness), to “chill out.” In this way, as in the rat studies, behaviors that succeed in reducing anxiety are reinforced, and each subsequent social event is a bit more tolerable.

Here's how it works in the brains of rats (and by implication in the human brain), according to LeDoux:

Much has been learned about the brain mechanisms underlying passive and active coping in rats.  Freezing, the rat’s version of passive coping, is known to depend on a specific set of connections in the brain — specifically, between two regions of the amygdala: the one that processes incoming signals about the external world and the one that regulates innate reactions like freezing (via outputs to the lower brainstem). The active coping response, proactive avoidance, by contrast, requires that the information processed in the input region be redirected to a different output controller in the amygdala, one that engages goal-directed actions.... 

A major conceptual issue is how the re-routing takes place naturally within the amygdala, allowing the shift from freezing to active coping and thereby preventing pathological avoidance and allowing proactive avoidance and agency.  Recent work has shown that connections from the prefrontal cortex, a region important in behavioral control, to the amygdala are important in allowing the shift to take place. 

The amygdala has long been thought of as the accelerator on the threat train, and the prefrontal cortex the brakes.  But the new work suggests that the prefrontal cortex is not just the brakes, but also the switch that controls the track on which the train travels.  Figuring out how to more effectively engage the prefrontal cortex in this switching will hopefully suggest new treatment approaches.

Your Brain On MDMA--- 

source-asap science

Your Brain and Drugs Marijuana part 1

Today we see a lot of " WEED"  addiction ...let us understand what exactly it does to your  brain..

please go through the video.....Thanks