Munchies and More: The Effects of Marijuana on the Brain

Biology 202
2002 Second Paper
On Serendip

Munchies and More: The Effects of Marijuana on the Brain

Kathryn Fong

To many, marijuana is seen as a horrible narcotic that causes many physical and social problems. To others, it's a harmless drug that gives the body a relaxing sensation. Marijuana can be found on many college campuses and high schools. It is estimated that at least 70 million Americans have tried it, and of those people, 10-14% become dependent of the drug (1). Marijuana is often referred to as the "gateway" drug, leading the user to more serious narcotics. Marijuana users experience different sensations, from excessive mellowness, fuzzy memory, to the munchies. Some of the typical effects are impairment of memory, alteration of memory, motor coordination, posture, cognitive ability, and sensory perception. So what is it in marijuana that keeps users wanting more?

The active ingredient in marijuana is delta-9-trans-tetrahydrocannabinol, or THC. The structure of THC is very similar to the endogenous cannabinoids, or endocannabinoids for short, which are naturally occurring chemicals in the body (1).The THC binds to the receptors of the endocannabinoids, and activates the neurons, causing the different sensations experienced during a high. These receptors are spread throughout the brain. THC affects the central nervous system, as well as the peripheral tissue systems. THC can reduce pain, lower body temperature, and enhance appetite. It can also be used for anti-inflammatory, bronchodilatory, and anti-convulsant, which is why THC is used for medicinal purposes. THC is used as a popular treatment for glaucoma by reducing ocular pressure, and for neurological disorders such as multiple sclerosis, Huntington's Disease, and spinal cord injury (4).

The THC acts on the receptors of the endocannabinoids. Two known endocannabinoid receptors are CB1 and CB2, which are found in the nervous system and the periphery nervous system, respectively. The receptors are coupled with G-proteins and mediate the inhibition of adenylyl cyclase activity, which in turn reduce the production of cyclic AMP, cAMP. The reduction of cAMP formation blocks calcium ion flow into the cells, which would disrupt the formation of action potentials. This may attribute to some of the side effects to marijuana use (4). Cyclic AMP and calcium ions regulate several neurotransmitters, including acetylcholine and dopamine (1). This may account for the nice and mellow feeling people experience when smoking pot.

The precise physiopathological responses between the stimulation and inactivation of endocannabinoid receptors are still unclear, however, it is known that the performance of the nervous system and the peripheral processes, such as modulation of neurotransmitters, control of immune, gastrointestinal, reproductive, and cardiovascular systems are impacted. By observing the actions of the CB1 receptor, researchers are able to determine different response pathways. The actions of the CB1 receptors interact with thermoregulatory systems in the body. CB1 receptors also interact with sensory perception such as hearing, color vision, and touch. Motor responses are also affected by CB1 receptors, some motor responses being movement, coordination, posture, and muscle function. THC has a high affinity to CB1 receptors, which may account for the different sensations when one gets "high. Often times, a person under the influence of marijuana feels an increase of body temperature, hallucinates, seeing colors and objects that are not really there, has trouble walking, or staggers around. It is the binding of the THC to the receptors that cause this. The CB1 receptors and their corresponding enzymes and proteins can be found in the thalamus, hippocampus, cortex, striatum, substantia nigra, and cerebellum. This shows that endocannabinoids and their substrates have a role in motor and cognitive response (2).

THC may also affect the endocrine system. The CB1 receptors are found in the hypothalamus of the brain, which regulates the secretion of pituitary hormones. The release of the pituitary hormones can also lead to the secretion of adrenocorticotropic hormones (2).

It is still unknown if marijuana is addictive, or contains any addictive agents. An experiment was done with monkeys, in which every time they hit a lever, they would get injected with THC. After the monkeys figured out how to operate the levers, they hit the lever about 30 times per minute. This however, does not prove whether the monkeys were addicted or whether they just enjoyed the sensation, and felt it was a reward. In humans, about 10-14% of users become dependent. There are many treatment programs that help those addicted to marijuana (3). It may more difficult to diagnose a marijuana addict because the symptoms of marijuana addiction are not as noticeable as symptoms of different dependence, such as alcoholism (1).

One thing that I wanted to find information on, but was not able to was about the "munchies". My friend and I came up with the same question: Do people actually experience the "munchies", or are it because they heard that everyone experiences "munchies" after they smoke marijuana, so they get the "munchies" too. Are the "munchies" a physiological effect of marijuana use, or just a psychological effect? Though I did not get an answer, I think it may be related to THC. This question may require more research for the future.

 

References

1) Carrol, Linda, Marijuana Effects: More Than Just Munchies, New York Times, January 29, 2002

2) endogenous signaling system: chemistry, biochemistry, and physiology, from the Internet Journal of Science - Biological Chemistry

3) Hooked on Hash, from New Scientist, 2000

4) The Pharmacology and Biochemistry of Cannabinoid Receptors, May 1997

 

 

Continuing conversation
(to contribute your own observations/thoughts, post a comment below)

01/24/2006, from a Reader on the Web

In regards to Katheryn Fong's Marijuana study. The Munchies are a very real thing. When I did use marijuana by smoking or drinking a tea. I did notice that even when I had something to eat an hour previously I had the sensation of being hungry again. I knew I couldn't be physicly hungry again and I was eating insane amounts of food. I also noticed that I had the cravings for sweets one minute and salty fatty foods the next. I believe that the body wants something for the THC to bind with, preferably fats. The body may be doing this for some reason but I will be conducting studies in a few years myself. I no longer use Marijuana but felt this could help.

Additional comments made prior to 2007
Yes, the munchies are real... from what I have heard/experienced, your body craves the food because, for whatever reason or another, eating balances some kind of chemical equation in your body and you come down from your high. So in effect your body craves different foods to balance itself out, and bring you down from your high. After you eat, as anybody can tell you that has smoked marijuana, you get very tired. I would usually fall asleep watching TV for a few hours in the middle of the day even though I had only been awake maybe 6 or 7 hours ... David L, 14 May 2006

 

 

"Marijuana dependence?" You are one of the people who create that myth and the myth that it is a dangerous narcotic ... Jared Barnett, 28 February 2007

 

 

i think marijuana is fine it's herbal and the doctors give it to thier patience someitimes ... Cassy, 10 December 2007

Hey I did some research

Hey I did some research myself and I called a doctor who does research in Colorado and he was saying that the reason for "munchies" is because there's a chemical in marijuana that has the same composition as a chemical your body releases to let you know you're hungry. It's an instinctual reaction he was saying and also has the effect of making you crave more marijuana, so when you smoke you want to smoke more but the feeling goes away after you stop smoking.

munchies

from my expeirience with marijuana, the munchies only seem to occur when i am bored or have nothing better to do. however when i start to eat, there becomes a sense of joy in eating and i am able to eat in large quantities (enough food for 4 people to be satisfied). i am 6 foot and weigh 150 pounds, so eating large quantities of food isnt a normal occurance and i beleive that it is in this ability induced by marijuana that there is a sort of pleasure in eating that is enhanced by the drug which makes it a more enjoyable activity coupled with an almost bottomless stomach, thus inducing the so called "munchies." however, this is just my veiw on how my body reacts to marijuana. what is true for some may not be true for others.

Questions about marijuana

Would you say that marijuana would be good for a person who has swelling around spinal cord?

Would say that marijuana is life threatning, with one who has no medical ailments?

munchies...

marijuana can reduce pain lower body temp, increase appetite.

not quite a quote but that was listed in this. then one would go on to wonder if marijuana causes munchies. read your own research

Marijuanna

Marijuanna does not reduce pain, in fact, the latest studies shows it actually increase sensibility to pain, the munchies are caused by the area affected by the drug, that area controls hunger, memory, sensorial perceptions, circulatory system (increase of up to twice the regular heart beat), it also causes constrictions of vasculatory systeme in the brain, thus causing memory gaps. That side effect can last up to a month after taing the drug, That drug is not harmless, it IS addictive, scientist are more and more convince that POT can cause cancer since it has more than twice the tar of cigarette, and contain 15 times more combustion particules that are known to cause cancer.
Pot is now known to cause hepatitis "C" and liver damage, if abused constitently for a long periode of time. it also damage and reduce the number of sperms, stomach, groth glands, reduce your drive to do things and motivations, etc... still think it's safe ? You must be high not to see all the bad things pot does behind the illusionnary mellow feeling. stay away, cause "mary wanna" hurt you

Natural high obtained by sports, hobby's, and friendly "sober" gathering, is always the best, cannabinoid are actually naturally produced by the brain with no side effect. Be yourself, be free, be clean...

Marijuana lowers blood pressure

Marijuana lowers blood pressure, and causes you to not feel pain. Unlike above me, here's a few links:

http://marijuanacannabis.com/marijuanacannabis_painkiller.html
http://www.drugpolicy.org/marijuana/medical/challenges/litigators/medical/conditions/pain.cfm
http://www.theage.com.au/articles/2003/05/21/1053196618331.html

A message to all people like this: Please actually research information before trying to waste our time with unintelligible bullshit.

Marijuana does NOT cause hepatitis C

The post above is misleading and biased. Pot does not cause hepatitis C anymore than it causes HIV/AIDS. This is such a joke. Hepatitis C is a blood-borne infection caused by exposure to the blood of an infected person. This claim is ridiculous. Hepatitis C is caused by injection drug use, blood transfusion, Sexual exposure, or Body piercings/tattoos etc.

It is true that pot smoke contains more tar but I firmly believe that cigarettes cause far greater harm. Cigarettes kill more people than suicide, homicide and traffic accidents combined. Pot has never caused a single death...

Alcohol is also far worse as far as causing damage to health and to society.

It is a personal choice one makes, but it should be based on personal experience not on the words of some misinformed anti-drug zealot. People (adults) should try it for themselves. For the record I used to smoke but quit because I got severe munchies.

marijuana isnt addictive.

marijuana isnt addictive. people who get addicted usually smoke blunt wraps and that has tobacco in it so thats what they get addicted to. and the munchies thing is true

if munchies aren't real than

if munchies aren't real than i shouldn't be able to eat like two pizzas. like i think it would be pretty hard to convince me to do that. just saying

"Munchies"

I believe that one's body has the desire to eat when high because eating will restore the balance in your body; it will bring you down from your high. There will be a particular craving for sweet or fatty foods, because that is what will bring your high down the fastest. There is no scientific data I can find to support this belief, just lots of first hand experience. I only get the munchies when I have smoked a considerable amount. I find if I smoke just a little, I have a functional "high", which is a state where I will do other activities and the marijuana has a relaxing and beneficial effect. If I smoke a lot, then I feel a bit overwhelmed and out of it, I get food cravings, and after eating, feel better.

It is all relative. Each person will react differently and have different levels of tolerance. Nevertheless, craving food is a common effect.

Finally, marijuana, especially the strains of genetically modified and enhanced marijuana available since the early 1990s, is very addictive to people predisposed to addictive behavior. It is a psychological addiction with some minor uncomfortable physiological effects from withdrawal. Don't let the "psychological addiction" confuse you- it is a real addiction.

The main issue with marijuana addiction is that it isn't devastating. It just makes you function at a lower level. It can reduce anxiety, tension and pain, but it also makes you a bit dumber and slower- which is relative. I know many people who smoke and are still high earning educated professionals- but they are really intelligent- they have the brain cells to spare. Being dumber for them is still way above average. Be careful of such people- they can mislead you into believing you can do the same. Most chronic smokers (not occasional or casual smokers, I am referring to people who smoke every day) who are past college age are idiots- harmless and even funny at times- but idiots nonetheless.

Oh please. Munchies are

Oh please. Munchies are definitely real. I was stoned every day for about a year when at university. Unfortunately, they r very real. PersonallY i think it's because you 'spin out' like when drunk but you feel dizzy almost from smoking too much. You also start to feel shaky. I think eating the food gets you back in your body. I'm serious. You get so 'spaced out' that you panic and eating is the only way to turn your brain off and stop a major panic attack. Seriously that's my experience after as I say a year of heavy daily smoking, and I'm female. I haven't done any drugs for 8 years now. And I don't drink. For vanity and spiritual reasons! hehe. I mean horses/animals don't drink do they, and they're lovely.

I spent a lot of time

I spent a lot of time thinking about this one day with my brother. I came up with a few theories. First is about the shakes, hypoglycemics often experience the shakes when they are low on blood sugar. The best cure for this of coarse is simple sugars, aka crappy junk food. Another thought came to me when I realized that I don't get the munchies, and as so happened on that night night I was over at my cousin's and all he did was watch TV and eat junk. I on the other hand talked with my brother about the beauty in the randomness and infinite complexity involved in the growth of a tree. I also recall hearing at some point that weed makes you horny. I'd now like to draw on Plato's theory on personality. Plato believed that there were three elements involved in someones personality. Plato, I'm sure by the way, was an avid user of marijuana. He did after all travel to India, and the middle east during a time when marijana or ghanja, was prevalent. So plato said that the first area is desire, desire to eat, desire to be comfortable, desire to do it. The second is emotion. The ability to love, to fight and die, courage, spirit, sadness, altruism. The final is intellect, the desire to learn and increase knowledge, and the ability to analyze concepts, and synthesize theories. Marijuana, I believe, causes one to stand out, and all the others to dim. I hope you can all find examples in your own lives to back up what I'm talking about.

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