How the Chemicals in Marijuana Work in the Brain

October 9, 2014 · Posted in Neurochemistry · Comment 


Raphael Mechoulam, who first synthesized THC, the main ingredient in marijuana, gave the history of marijuana and its receptors in the central nervous system in a plenary talk at the 2014 meeting of the International College of Neuropsychopharmacology. In Syria hundreds of years ago the drug was named ganzigunnu, meaning “the drug that takes away the mind.” It has also been called azalla, meaning “hand of the ghost.” Among the 100 compounds in marijuana, the best-known ingredient is delta-9-tetrahydrocannabinol (delta-9 THC), which produces most of the actions of the drug. There is another active ingredient, cannabidiol (CBD), which has calming and anti-anxiety effects, but is present in very low levels.

The brain has cannabinoid receptors that respond to ingredients in marijuana in addition to other chemicals produced in the brain. They modulate calcium ions and decrease the release of many neurotransmitters.

THC acts at CB-1 receptors, producing the high. The CB-1 receptor is synthesized on demand, post-synaptically, and is transferred to the pre-synaptic terminal where it decreases calcium and transmitter release. Consistent with marijuana’s appetite-stimulating properties (“the munchies”), if the CB-1 receptor is blocked in animals, they lose their appetite and die of hunger.

There are also low levels of CB-2 receptors in the brain, whose activation does not cause a high, and whose levels may increase dramatically in pathological situations. Activation of the CB-2 receptor is anti-inflammatory and, in the same way that the immune system acts against foreign proteins, CB-2 acts as a protector against non-proteins.

CBD does not bind to any cannabinoid receptors, but its actions are blocked by cannabinoid antagonists.

There are two chemicals in the brain (endogenous ligands) that act at cannabinoid receptors—anandamide and 2-arachidonoylglycerol (2-AG). They are soluble only in lipids (not in water), and have never been given to people. In animals, 2-AG has neuroprotective effects, decreases the size of a stroke by 60%, and increases recovery from stroke.

Marijuana and CBD in particular have also had beneficial effects in people. Marijuana decreases the nausea and vomiting associated with chemotherapy in children, has anti-inflammatory effects in rheumatoid arthritis (decreasing inflammatory marker TNF alpha), and has anti-diabetes and anti-convulsant effects.

In 2012, researcher F. Markus Leweke and colleagues showed that CBD was about as effective as the atypical antipsychotic amisulpiride in alleviating the psychotic symptoms of schizophrenia. CBD’s other effects include reducing anxiety and improving psoriasis by increasing DNA methylation (Pucci et al. 2013).

It seems possible that some of these myriad effects of marijuana and endogenous ligands at CB receptors could be exploited for clinical therapeutics, as Mechoulam endorses, but when and how that will take place remains an unanswered question.

Editor’s Note:  Despite all these potential positives of CBD, it should be noted that its levels are very low in marijuana, and that heavy smoking of marijuana has substantial adverse effects. These include low motivation, a doubling of the risk of psychosis, a hastening of the onset of bipolar disorder and schizophrenia, and cognitive impairment, as well as some changes in brain structure seen via magnetic resonance imaging (MRI). It may be becoming legal in many states, but is a bad idea for those at high risk for mood, anxiety, or bipolar disorders or for schizophrenia. More uterine cancer though uterine cancer's cause is unknown, there are many factors that will put a woman at risk, including: over age 50, endometrial hyperplasia, using hormone replacement therapy, obesity, using tamoxifen, being caucasian, having colorectal cancer. These are, however, only the first set of results. Net news-medical. By submitting this query, you agree to abide by this policy. viagra woman herbals Net news-medical. nbsp 7) nbspnbsp active@ iso burner 2. innovative oral treatments of uterine leiomyoma. side effects viagra young men can you get samples viagra However, prolonged and severe anemia that is not treated can cause heart problems. nbsp applied radiology 20007:15-20. Women's health about our center bleeding bone health cancer contraception and family planning cosmetic procedures full size staff shot sexual assault response program/rape crisis center female support groups topics and series resource centers breast health domestic violence eating disorders endometrial conditions fibroid care uterine fibroids uterine fibroid embolization gastrointestinal disorders gynecology heart health and cardiovascular disease infections menopause care pelvic muscle function and continence pelvic pain menstrual-related conditions minimally invasive gynecologic surgery obesity, diet and exercise ovarian cysts pelvic function pregnancy and childbirth adolescent gynecology general and genitourinary gynecology sexual function anxiety sexually transmitted diseases depression thyroid conditions view by distinguished centers select center cancer care heart care orthopedics women's health view by featured programs select featured program emergency medicine radiation oncology surgery view by areas of interest select area of interest allergy anesthesiology arthritis bariatrics behavioral health breast health breast surgery cardiothoracic surgery cardiovascular disease/cardiology colorectal surgery community programs dermatology diabetes ear, nose throat emergency medicine endocrine surgery endocrinology eye care family practice gastrointestinal disease/gastroenterology general surgery gynecology women's health heart care hematology home health immunology infectious diseases internal medicine joint replacement kidney disease medical oncology medicine minimally invasive surgery nephrology neurology neurosurgery obesity occupational health oncology ophthalmology oral medicine otolaryngology orthopedic surgery pain management pathology physical medicine plastic/reconstructive surgery podiatry psychiatry pulmonary medicine radiation oncology radiology radiosurgery rehabilitation respiratory disease rheumatology robotic surgery sleep medicine sports medicine surgery surgical oncology thoracic surgery trauma urology vascular surgery weight loss wellness women's health helpful links find a doctor make an appointment locations directions special distinction accreditation for aria's health center seek health. K. viagra online kaufen forum viagra kaufen uk In some cases, it can be associated with uterine fibroids, endometrial polyps, polycystic ovary syndrome (pcos), intrauterine device (iud) or birth control usage. The severity of these symptoms may be underestimated, as some women who suffer from symptomatic fibroids have become accustomed to the heavy menstrual bleeding, pain and pressure that they can cause.