why do humans have cannabinoid receptors in the brain?
492151
The cannabinoids are among the most common and most important of the neurotransmitters.  They are a bit unique in how they function, travelling from cell membrane to cell membrane instead of the normal process of release of neurotransmitters by individual cells in vesicles.  This different pathway allows for them to not only send their own signals, but also have a moderating effect on other neurotransmitters.  This allows for the fine-tuning of certain signals.\n\nMany of the medical uses for cannabinoids that are not produced by the body (such as Cannabis) involve taking advantage of this reduction in the action of other neurotransmitters: numbing of pain, reduction of stress-related effects, restoration of appetite to normal levels, etc.  As said before, the receptors aren't there for the sake of getting high, it's just that other similar chemicals can act with these same receptors.
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Effects on the Brain\n\nScientists have learned a great deal about how THC acts in the brain to produce its many effects. When someone smokes marijuana, THC rapidly passes from the lungs into the bloodstream, which carries the chemical to organs throughout the body, including the brain.\n\nIn the brain, THC connects to specific sites called cannabinoid receptors on nerve cells and influences the activity of those cells. Some brain areas have many cannabinoid receptors; others have few or none. Many cannabinoid receptors are found in the parts of the brain that influence pleasure, memory, thought, concentration, sensory and time perception, and coordinated movement4.\n\nThe short-term effects of marijuana can include problems with memory and learning; distorted perception; difficulty in thinking and problem solving; loss of coordination; and increased heart rate. Research findings for long-term marijuana abuse indicate some changes in the brain similar to those seen after long-term abuse of other major drugs. For example, cannabinoid (THC or synthetic forms of THC) withdrawal in chronically exposed animals leads to an increase in the activation of the stress-response system5 and changes in the activity of nerve cells containing dopamine6. Dopamine neurons are involved in the regulation of motivation and reward, and are directly or indirectly affected by all drugs of abuse.\n\n\nEffects on the Heart\n\nOne study has indicated that an abuser's risk of heart attack more than quadruples in the first hour after smoking marijuana7. The researchers suggest that such an effect might occur from marijuana's effects on blood pressure and heart rate and reduced oxygen-carrying capacity of blood.\n\n\nEffects on the Lungs\n\nA study of 450 individuals found that people who smoke marijuana frequently but do not smoke tobacco have more health problems and miss more days of work than nonsmokers8. Many of the extra sick days among the marijuana smokers in the study were for respiratory illnesses.\n\nEven infrequent abuse can cause burning and stinging of the mouth and throat, often accompanied by a heavy cough. Someone who smokes marijuana regularly may have many of the same respiratory problems that tobacco smokers do, such as daily cough and phlegm production, more frequent acute chest illness, a heightened risk of lung infections, and a greater tendency to obstructed airways9. Smoking marijuana possibly increases the likelihood of developing cancer of the head or neck. A study comparing 173 cancer patients and 176 healthy individuals produced evidence that marijuana smoking doubled or tripled the risk of these cancers10.\n\nMarijuana abuse also has the potential to promote cancer of the lungs and other parts of the respiratory tract because it contains irritants and carcinogens9,11. In fact, marijuana smoke contains 50 to 70 percent more carcinogenic hydrocarbons than does tobacco smoke12. It also induces high levels of an enzyme that converts certain hydrocarbons into their carcinogenic form—levels that may accelerate the changes that ultimately produce malignant cells13. Marijuana users usually inhale more deeply and hold their breath longer than tobacco smokers do, which increases the lungs' exposure to carcinogenic smoke. These facts suggest that, puff for puff, smoking marijuana may be more harmful to the lungs than smoking tobacco.\n\n\nOther Health Effects\n\nSome of marijuana's adverse health effects may occur because THC impairs the immune system's ability to fight disease. In laboratory experiments that exposed animal and human cells to THC or other marijuana ingredients, the normal disease-preventing reactions of many of the key types of immune cells were inhibited14. In other studies, mice exposed to THC or related substances were more likely than unexposed mice to develop bacterial infections and tumors15,16.\n\n\nEffects of Heavy Marijuana Use on Learning and Social Behavior\n\nResearch clearly demonstrate
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The main active chemical in marijuana is THC (delta-9-tetrahydrocannabinol).
1102367
You must have read something old.  Modern science, with eeg's, CT scans, MRI's, show that all parts of the brain are used.  Not all parts are active at the highest level, all of the time.  Humans use all of their brain capacity,
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The brain cells or neurons in our brain die every day. No new cells are produced; still the original stock of these neurons with which we are born is so huge ( there are trillions of them) that we do not feel the loss of neurons till very late in our life. Beyond the age of 70-75 the loss is felt as the memory begins to fade our reflexes our actions deteriorate.\n Drugs and smoking badly affects them and speeds up the process of deterioration.
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because the thc in marijuana opens up the blood vessels making them less constricted, and the oxygenated blood in the cappilaries becomes more prevelant in the eyes, which is the same reason why people with glaucoma(acute constricting of blood vessels in the eyes) use marijuana for their condition.
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People are classifying things wrong.\n\nStimulants make you more awake and makes parts of your brain more active, depressants make you sleepy and make parts of your brain less active, and hallucinogens cause hallucinations (you see/hear/feel things that aren't really there).\n\nStimulants ("uppers"):\nCaffeine\namphetamine/methampetamine/"ice" (a form of freebase methamphetamine)\nCocaine/crack (a form of freebase cocaine)\nNicotine\n\nDepressants ("downers"):\nAlcohol\nValium/Xanax (benzodiazepines, prescribed for anxiety)\nHeroin/morphine/codeine (these are opiates)\nDemerol/Fentanyl/Nalone/oxycontin (synthetic opiods, used as pain killers)\nNitrous Oxide (aka laughing gas, used for anesthesia)\nEther (formerly used for anesthetia)\n\nHallucinogens/Psychadelics:\nLSD (aka "acid")\nPsilocybin ("magic mushrooms")\nPeyote/mescaline\n\nSome other common drugs need special classification.\n\nPCP and Ketamine (Special K) are horse tranquilizers.  in humans, they have bizarre properties, because the way they work is strange (they bind to a site inside the muscarinic acetylcholine receptor, so they can only affect regions already active).  They have some properties of depressants (people are said to feel no pain, and their thinking becomes muddled), they have some hallucinogenic qualities (some people hallucinate on some occasions), and they have some traits of stimulants (people can grow active or violent on PCP--users are notorious for being hard for police to get under control).  Some classify PCP, ketamine, and Nitrous Oxide as dissociatives, which form their own special class.\n\nMarijuana is likewise odd.  Hallicinations can happen, but are generally rare.  Many people find that it makes them sleepy, and it definitely is known to delay your reaction times, but it isn't like a traditional depressant.  Finally, it has some (very few) traits that are seen as stimulatory, because some people like to be incredibly active while using them (a competitive snowboarder got caught with THC in his system a few years ago), and it can cause extreme paranoia (generally associated with stimulants).  In my opinion, it is best that cannabinoids are considered their own seperate class of drugs.\n\nMDMA (aka Ecstacy, E, X) is another oddball.  Some people put E along with drugs like LSD and mescaline into a category called "entheogens," as these drugs are all known to make people highly introspective.  It is often called a psychadelic, but primarily because it works on the same sorts of receptors that psychadelics work on (aka serotonin receptors).  The best category for MDMA is enactogen, which applies to a subset of psychadelics that don't necessarily cause hallucination (like LSD).  Though MDMA is an amphetamine derivative, the most significant of its affects are not stimulatory.  The term enactogen applies to these sorts of drugs that exert their primary effects on a person's emotional state.  Stimulants and depressants are defined by the levels of mental arousal they give, and psychadelics are defined by the alteration of senses.
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Are you sure you aren't doing any illegal substances like marijuana? It has been known to cause people to hallucinate and have phobias for no reason.
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Yup. The active ingredient, I think the abbreviation is THC, sticks around in the body for years. It also can damage sperm cells (knocks their tails off).\n\nAs the saying goes, "Pot smokers can't remember the brains they've lost."
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I'm not sure sorry! Can imagine it would be difficult to find a really good answer as well - knowing an exact number would require some research and willing subjects... which'd require money... which'd mean there'd need to be some good cause for the research such as money to gain or else really useful info.. and to be honest I don't think knowing the exact number of brain cells killed when you inhale a whip it would provide either! But if you find out, please let us know...! Just for interests sake.\n\nAnyways, I really don't think anyone who's willing to sacrifice their brain cells for a 30 second high could've had all that many to begin with... unless they're like depressed as hell or something. Actually no, a depressed person with a brain would either get help, or at least choose a form of drug with a longer lasting high. So I reckon people that use whip-it lose hardly any brain cells at all - they might lose a few the 1st time, but as most of the cells making up their brain are non-functional, it's probably no big deal.
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LSD (lysergic acid diethylamide) is one of the major drugs making up the hallucinogen class of drugs. Hallucinogens cause hallucinations—profound distortions in a person’s perception of reality. Hallucinogens cause their effects by disrupting the interaction of nerve cells and the neurotransmitter serotonin. Distributed throughout the brain and spinal cord, the serotonin system is involved in the control of behavioral, perceptual, and regulatory systems, including mood, hunger, body temperature, sexual behavior, muscle control, and sensory perception
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It is what is commonly referred to THC the active ingredient found in marijuana.It is what causes the feeling associated w/using pot.
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Addictive Potential\n\nLong-term marijuana use can lead to addiction for some people; that is, they use the drug compulsively even though it interferes with family, school, work, and recreational activities. Drug craving and withdrawal symptoms can make it hard for long-term marijuana smokers to stop using the drug. People trying to quit report irritability, sleeplessness, and anxiety(38). They also display increased aggression on psychological tests, peaking approximately one week after the last use of the drug(39).
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BECAUSE YOU'RE HIGH!!! You can't really read minds!!!! You just think you can because you are f***ed!!!\n\nIf you really think you did, it might just have been that the way the drugs affected your mind and perception made you aware of things that you would not notice sober. Maybe you were just able to be more observant of people's body language, tone, and all those subtle cues that most people do not usually pick up on.
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The chemical in marijuana, THC, is absorbed by fatty tissues in various organs. Traces of THC can be detected by standard urine and blood tests for about 2 days up to 11 weeks depending on the persons metabolism, how much they smoked and how long they smoked. THC can be detected for the life of the hair. Again, the sensitivity of the test ranges from person from to person depending on many factors including the amount of body fat, differences in metabolism, and how long and how much they smoked.
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neurogenesis was produced in the hippocampus area of the brain using cannaboids ,marijuana studies ,look at my q and a ,the question about the phenomenom of marijuana, the studies are cited there or the information you need to find the works cited are there
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Because of the hypothalamus in our brain.