cannabisnews.com: Should MJ Use for Medical Reasons Be Allowed?










  Should MJ Use for Medical Reasons Be Allowed?

Posted by CN Staff on June 12, 2005 at 10:28:35 PT
Opinions 
Source: News-Leader  

Pro: Should Marijuana Use for Medical Reasons Be Allowed?Marijuana has been used for medicinal purposes for more than 4,000 years. Twelve states have approved marijuana for medical use, but with the most recent Supreme Court ruling, its use has been subject to federal law. The court essentially criminalized its use for medical purposes by the user as well as the prescribing physician.
Putting aside the legal issues involved, which is certainly a source of intense debate, I wanted to speak to the medical uses of marijuana.The medical use of marijuana is controversial within the medical community. In order to take an objective look at the issue, the White House Office of National Drug Control Policy asked the Institute of Medicine to do a study of the health benefits and risks of marijuana. This study was started in January 1997 and its conclusions published in 1999. It did an extensive review of the relevant scientific literature, consulted social and biomedical scientists, and visited HIV/AIDS clinics.While the study's conclusions were not an endorsement of medical marijuana, it found enough positive aspects of marijuana to recommend further research. It found that marijuana shows promise when conventional therapies have failed. There has been research in this area since that time, but unfortunately because of the illegality of marijuana and the strict regulations involved with it, research has been difficult and sparse.Marijuana has shown promise through research and experience to be helpful in conditions that are not responsive to conventional therapies. This includes treatment of multiple symptoms of advanced AIDS, as well as chronic intractable pain.Of course with any therapy there are risks and complications associated with it, including the medicines we currently use for these conditions. The toxic effects of smoking marijuana are well known. It is much more toxic than tobacco, and the risk of lung disease and cancer are substantial with prolonged use.Oral forms of marijuana (marinol) are used currently to treat nausea and vomiting of cancer therapy. Unfortunately it is slow acting and not as effective as the smoked form. Vaporization of marijuana is promising as it avoids the toxic effects of smoking and is fast acting.In light of the present controversy with medical marijuana, I recommend that we ease restrictions on research so we can better determine the benefits and risks of marijuana. It should be made available to patients with pain associated with terminal illness that have failed other therapies.This issue has hit me personally. My brother died of cancer several years ago, and he smoked marijuana illegally to relieve his suffering when other therapies failed. I would hate to think he would be treated as a criminal.Note: Easing restrictions on research would help determine risks and benefits of marijuana.By Dr. Mark Bult: Home: Bolivar -- Occupation: Founder and director of CMH Institute of Pain Management Con: Should Marijuana Use for Medical Reasons Be Allowed? Legalizing use of marijuana for medicinal purposes would raise public safety concerns.There are sound public health and safety reasons for Congress to not legalize the use of marijuana for medicinal purposes.First, there are no generally accepted studies supporting the proposition that smoking marijuana is beneficial to one's health. Studies do indicate that THC (the primary active chemical out of more than 400 chemicals found in a marijuana plant) can be useful for the treatment of some medical problems. Synthetic THC is an FDA-approved medication available by prescription in capsule form since 1985. Synthetic THC decreases nausea in cancer chemotherapy patients and increases appetite in people with AIDS.However, studies conclude that smoking marijuana is not recommended for any medical use due to numerous adverse medical effects. Smoking one marijuana joint has the same effect on the respiratory system as one receives in smoking five filtered tobacco cigarettes. There are links between marijuana use and mouth, throat and lung cancers (a marijuana joint has three to five times higher tar levels than a tobacco cigarette and the same, if not more, cancer causing ingredients as a cigarette). Smoking marijuana causes brain changes similar to those caused by cocaine, heroin and alcohol.Marijuana causes dependency, with more teens entering drug treatment with a primary diagnosis of marijuana dependence than for all other illicit drugs combined. The earlier youth begin using marijuana increases the probability they will use and become dependent on other illegal drugs. Short-term effects of marijuana use include memory loss, distorted perception, problem-solving difficulties and anxiety.Second, there are public safety concerns. This office has prosecuted vehicular manslaughter and assault cases where the defendant was under the influence of marijuana. A national study of trauma room admissions revealed that 15 percent of patients injured while operating a car or motorcycle had been smoking marijuana.Finally, legalization of marijuana for medicinal purposes increases the risk of diversion of marijuana into illegal channels. The Supreme Court in its recent opinion cites an "indiscriminate and uncontrolled pattern of sale to thousands of persons among the general public, including persons who had not demonstrated any recommendation or approval of a physician and, in fact, some who were not under the care of a physician, such as undercover officers," and noting that some people who had lawfully obtained marijuana "were reselling it unlawfully on the street."Public policy should be driven by facts, or as we instruct juries, from viewing the evidence free of any sympathy, bias, prejudice or fear. One sympathizes with those suffering from medical ailments. However, a dispassionate viewing of the evidence does not support the legalization of marijuana for medical purposes.By Darrell Moore: Home: Springfield -- Occupation: Greene County ProsecutorSource: Springfield News-Leader (MO)Published: June 12, 2005Copyright: 2005 The Springfield News-LeaderContact: letters springfi.gannett.comWebsite: http://www.springfieldnews-leader.com/Related Articles & Web Site:Medical Marijuana Information Linkshttp://freedomtoexhale.com/medical.htmWhen Judicial Fantasies Take a Toll http://cannabisnews.com/news/thread20847.shtmlClarity on Marijuanahttp://cannabisnews.com/news/thread20845.shtmlCongressional Leaders Should Act To Protecthttp://cannabisnews.com/news/thread20843.shtml

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Comment #6 posted by Hope on June 15, 2005 at 07:41:55 PT
From Comment 1
"With over 7 million people using cannabis weekly or more often in the US alone..."As many as that is, it's probably a huge, huge, huge under estimation.A funny thing I've noticed about people and their awareness of what is going on around them every day is that those people that say, "I don't know anyone who uses marijuana" are always people who are antis or prohibitionists, or are at least going along with the idea, to some degree. They don't know because no one, who is aware of their tendency, is ever, ever going to let them have a clue. But, I can assure them, they do know and are even related to plenty of people who do use marijuana occasionally or often.The opposite is true, too. I know some people who say, "Everybody uses it." No, they don't. They are either just never around them or are ignoring their existence, because just as there are plenty of people who do use it, there are plenty of people who don't.There is no sin in marijuana use or non-use. There is no intrinsic evil involved in consuming the plant. There is, however, plenty of "sin" and "evil" involved in persecuting and belittling the people who do wish to use the plant.
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Comment #5 posted by BGreen on June 14, 2005 at 17:24:50 PT

This was in today's edition and it's great
This letter has to be an education for most of the readers of this paper.The Reverend Bud Green***************************************************************Greene County Prosecutor Darrell Moore was an obvious choice to write the "con" opinion against medical cannabis, joining other politicians, law enforcement and urine collectors who continue to perpetuate myths to keep their cash cow fed.The newest drug warrior mantra is "smoking marijuana is not medicine." They're trying to extrapolate the proven dangers of tobacco with cannabis without any proof that cannabis has ever caused a single case of cancer. As far back as 1975, studies showed that cannabis fights cancer by promoting programmed cell death (apoptosis) and by cutting off the blood supply to tumors.Vaporization of cannabis eliminates all of the tar and carcinogens caused by combustion, allowing a safe, rapid and thus easily adjustable delivery of medicine. This is especially beneficial to somebody who's vomiting and can't swallow a $25 synthetic Tetrahydrocannabinol capsule.Mr. Moore and the other pro-prison ideologists know about vaporizers. That's why vaporizers are illegal to possess and why prohibitionists repeat "smoking marijuana is not medicine" ad nauseam.The recently discovered endogenous cannabinoid system plays a major role in most functions of the human body. Cannabis is the only plant containing cannabinoids.Knowing this, why has the government consistently blocked research on this miraculous plant? The cash says "moo."Carl Smith, Ozark

Cash cow feeds on anti-pot myth
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Comment #4 posted by cloud7 on June 12, 2005 at 14:02:28 PT

...
Writer of the Con section of this article: "Darrell Moore Home: Springfield Occupation: Greene County Prosecutor"It is almost uncanny that everytime there is a hit piece on marijuana it invariably comes up that the person writing it is either in the business of:a) law enforcementb) urine testingc) the drug rehabilitation businessor d) some government droneFollow the money!
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Comment #3 posted by runderwo on June 12, 2005 at 14:02:00 PT

lungs
"The toxic effects of smoking marijuana are well known. It is much more toxic than tobacco, and the risk of lung disease and cancer are substantial with prolonged use."Gee, if you say so. Given the research in this area, I'd suggest that the onus is on you to show us the bodies."Oral forms of marijuana (marinol)..."Sigh. Oral SYNTHETIC THC (marinol)..."Synthetic THC is an FDA-approved medication available by prescription in capsule form since 1985."which 1. contains no CBD and is incapable of THC/CBD titration for optimal response in the individual, 2. costs upwards of $30 per dose, 3. is difficult to control the dose for the individual, leading to unwanted side effects, 4. is useless for nausea or asthma because of the manner of ingestion and delay between ingestion and response"There are links between marijuana use and mouth, throat and lung cancers (a marijuana joint has three to five times higher tar levels than a tobacco cigarette and the same, if not more, cancer causing ingredients as a cigarette)."THIS IS A BLATANT LIE! http://my.webmd.com/content/article/23/1728_57309
Where is the radioactive polonium in cannabis? Where are the carcinogenic nicotine impurities from air-curing? WHERE ARE THE BODIES?"Smoking marijuana causes brain changes similar to those caused by cocaine, heroin and alcohol."Another blatant lie.
http://my.webmd.com/content/article/70/80972.htm
Cocaine and heroin act directly on the dopamine system inducing a false pleasure. Cannabis acts on the CB1 and CB2 receptors. Any "false pleasure" is a result of the mild psychedelic and sedative effects from THC acting on the CB1 receptor. The withdrawal symptoms from cannabis are no more severe than that of caffeine, as opposed to the sickness that comes from nicotine or heroin withdrawal, or the life-threatening shock that accompanies alcohol withdrawal."Marijuana causes dependency, with more teens entering drug treatment with a primary diagnosis of marijuana dependence than for all other illicit drugs combined."Aside from this guy trying to play doctor and saying that a potential dependency outweighs the medical benefits, this statistic is flawed because it does not account for drug court referrals."The earlier youth begin using marijuana increases the probability they will use and become dependent on other illegal drugs."Irrelevant for a medical argument, and, even if it were true (what mechanism does marijuana use or what barrier does it break down to coerce youth into using harder drugs? or is it pushers? what about including alcohol and tobacco in the "gateway" argument?), it is also irrelevant for a legalization argument - one of the premises of a legalization argument is that unsupervised marijuana use by minors will be decreased by a regulated market. This is a straw man."Short-term effects of marijuana use include memory loss, distorted perception, problem-solving difficulties and anxiety."of RECREATIONAL doses. Many med users specifically avoid being "high". Does Montel have memory loss, distorted perception, problem-solving difficulties, and anxiety? What about Irv Rosenfeld the stockbroker? Peter McWilliams?"This office has prosecuted vehicular manslaughter and assault cases where the defendant was under the influence of marijuana."Okay? I suppose you've prosecuted the same where the defendant was under the influence of alcohol, or over-the-counter drugs like Nyquil or Robitussin, or excessively tired, or talking on a cell phone, or enraged - a condition that stoned driving mitigates? What implication is being made here?"A national study of trauma room admissions revealed that 15 percent of patients injured while operating a car or motorcycle had been smoking marijuana."This again means nothing. Aside from "stoned drivers are safe drivers":
http://cannabisculture.com/articles/1775.html
The presence of THC metabolites does not imply that the user was high at the time, and the user being high at the time does not imply that they are driving unsafely. What is the proportion of people who "had been smoking marijuana" (according to whatever test was used) in the general population? If it is not sufficiently lower than 15%, the hypothesis is invalid."The Supreme Court in its recent opinion cites an
    "indiscriminate and uncontrolled pattern of sale to thousands of
    persons among the general public, including persons who had not
    demonstrated any recommendation or approval of a physician and,
    in fact, some who were not under the care of a physician, such
    as undercover officers," and noting that some people who had
    lawfully obtained marijuana "were reselling it unlawfully on the
    street."Even if it is possible to abuse the system and some people might get high for recreational purposes (whether that is as big a problem as is claimed is left to another discussion), that is not a sufficient rationale for tying the hands of doctors and patients. Look at all the people abusing Oxycontin, Xanax, Ritalin, etc sold on the black market after being stolen or otherwise illegitimately obtained - is there a call to make those substances illegal for medical uses as well?"Public policy should be driven by facts, or as we instruct juries, from viewing the evidence free of any sympathy, bias,
prejudice or fear."Says the guy who is so scared of a minority obtaining cannabis for recreational purposes through the medical system that he would deny it to everyone."One sympathizes with those suffering from medical ailments."Notice "one sympathizes". Not "I sympathize". He could care less aside from keeping his job as prosecutor. If he were to advocate anything illegal, it could be shown to be a conflict of interest. A prosecutor is ALWAYS going to be a staunch defender of the status quo because they have no other choice."However, a dispassionate viewing of the evidence does not support the legalization of marijuana for medical purposes."Unfortunately, he has not provided any evidence whatsoever, only hearsay, myths, and lies. I'd like to see whatever evidence he is "dispassionately viewing" to support his outrageous viewpoint.FoM:
"Studies of long-term effects have conclusively demonstrated abnormalities in the lungs, laryngitis, rhinitis, and chronic obstructive pulmonary disease."On the other hand:Huber GL, Mahajan VK. 1988.
The comparative response of the
lung to marihuana or tobacco
smoke inhalation. In: Chesher G,
Consroe P, Musty R, Editors,
Marijuana: An International
Research Report: Proceedings of
Melbourne Symposium on Cannabis
2-4 September, 1987. National
Campaign Against Drug Abuse
Monograph Series No. 7 Edition.
Canberra: Australian Government
Publishing Service. Pp. 19--24.:"In contrast,
rats exposed to increasing doses
of marijuana smoke for one year
did not show any signs of COPD,
whereas rats exposed to tobacco
smoke did."
http://www.marijuana.com/marimed/ch3.html
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Comment #2 posted by jose melendez on June 12, 2005 at 12:28:11 PT

memory loss: insufficient cause for arrest
Re comment #1(b) http://www.niaaa.nih.gov/publications/aa63/aa63.htm Difficulty walking, blurred vision, slurred speech, slowed reaction times, impaired memory: Clearly, alcohol affects the brain. Some of these impairments are detectable after only one or two drinks and quickly resolve when drinking stops. On the other hand, a person who drinks heavily over a long period of time may have brain deficits that persist well after he or she achieves sobriety. Exactly how alcohol affects the brain and the likelihood of reversing the impact of heavy drinking on the brain remain hot topics in alcohol research today. We do know that heavy drinking may have extensive and far–reaching effects on the brain, ranging from simple “slips” in memory to permanent and debilitating conditions that require lifetime custodial care. And even moderate drinking leads to short–term impairment, as shown by extensive research on the impact of drinking on driving. http://alcoholism.about.com/cs/brain/a/aa000425.htm Brain Shrinkage and Alcoholic Behavior The shrinkage observed seems to be more extensive in the cortex of the frontal lobe, which is believed to be the seat of higher intellectual functions. This shrinkage generally increases with age, at least in men.Repeated imaging of a group of alcoholics who continued drinking over a 5-year period revealed progressive brain shrinkage that significantly exceeded normal age-related shrinkage. The rate of frontal cortex shrinkage correlates closely with the amount of alcohol consumed.But this shrinkage has also been observed in deeper brain regions, including brain structures associated with memory, as well as in the cerebellum, which helps regulate coordination and balance.Reversing the Effects A key goal of imaging in alcoholism research is to detect changes in specific brain regions that can be correlated with alcohol-related behaviors. Imaging of the cerebellum has linked both shrinkage and decreased blood flow to impaired balance and gait. Such impairment may cause falls among older alcoholics.Researchers do not agree on the effect this brain shrinkage has on memory loss and problem-solving skills. Some studies show no effect, while others have reported some loss in those skills, associated with alcohol-induced brain shrinkage. However, these effects are usually reversed with alcohol abstinence. Even quitting drinking for 3-4 weeks has shown to reverse the effects on memory loss and problem-solving skills.
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Comment #1 posted by FoM on June 12, 2005 at 11:32:19 PT

Medical Biology: Marijuana and The Heart
ScienceWeekMEDICAL BIOLOGY: MARIJUANA AND THE HEARTThe following points are made by Michael D. Roth (Nature 2005 434:708): 1) The discovery of cell-surface receptors that bind to the major active component of marijuana, delta-9-tetrahydrocannabinol (THC), has led to an explosion of research into the biological properties of marijuana and cannabinoids[1]. THC binds with equal affinity to two different receptors -- CB1 and CB2. CB1 is present at high levels on brain cells and at much lower levels on cells outside the nervous system. By contrast, CB2 receptors occur exclusively on cells outside the nervous system and in particular on cells of the immune system. This pattern of distribution suggests different functions for CB1 and CB2 that might be exploited therapeutically.2) New work by Steffens et al[2] evaluates whether THC can protect against the development of atherosclerosis, a disease in which a combination of fatty deposits and inflammation leads to "plaques" that obstruct coronary arteries, causing angina and heart attacks. The authors suggest that the immunosuppressive properties of THC, and specifically those mediated by CB2 receptors, might be developed to treat heart disease.3) The capacity of cannabinoids to regulate immune function is now well established. Exposing immune cells to THC alters their ability to produce certain signalling proteins called cytokines. When THC is administered to animals in vivo and to human cells in vitro, it suppresses the production of protective cytokines and increases the production of immunosuppressive cytokines. As a result, mice treated with THC fail to develop protective immunity against opportunistic infections and cancer[3]. Similarly, immune cells collected from the lungs of marijuana smokers produce lower than normal amounts of several cytokines and fail to produce nitric oxide (another intermediary in the immune system), severely limiting their ability to kill bacteria[4].4) Steffens et al[2] set the stage for their work by demonstrating that immune cells expressing CB2 receptors infiltrate atherosclerotic plaques in humans and in a strain of mice that is used to study atherosclerosis (ApoE-/- mice). In this mouse model, the animals develop progressive narrowing of their arteries as lipids and inflammatory cells called macrophages enter the walls of their blood vessels and produce plaques[5]. When low doses of THC (1 mg per kg body weight per day) were added to their diet, the progression of atherosclerosis was markedly slowed. Mice that were fed THC still had elevated levels of serum lipids but had fewer plaque-infiltrating macrophages when compared with controls, suggesting an effect on immune function.References (abridged):1. Di Marzo, V., Bifulco, M. & De Petrocellis, L. Nature Rev. Drug Discov. 3, 771-784 (2004)2. Steffens, S. et al. Nature 434, 782-786 (2005)3. Klein, T. W. et al. J. Leukoc. Biol. 74, 486-496 (2003)4. Shay, A. H. et al. J. Infect. Dis. 187, 700-704 (2003)5. Meir, K. S. & Leitersdorf, E. Arterioscler. Thromb. Vasc. Biol. 24, 1006-1014 (2004)Nature http://www.nature.com/nature--------------------------------Related Material:LONG-TERM EFFECTS OF HEAVY MARIJUANA USEThe following points are made by N. Solowij et al (J. Am. Med. Assoc. 2002 287:1123):1) In the current climate of debate about marijuana laws and interest in marijuana as medicine, one issue remains unresolved: Does heavy, frequent, or prolonged use of cannabis lead to a deterioration in cognitive function that persists well beyond any period of acute intoxication? Is the functioning of the brain altered in the long term? With over 7 million people using cannabis weekly or more often in the US alone, and the potential for increased physician recommendations for select patients to use cannabis therapeutically, answers to these questions are of significant public health concern.2. Past research suggested that gross impairment related to chronic cannabis use did not occur, but the evidence was inconclusive with regard to the presence of more specific deficits. Recent studies with improved methods have demonstrated changes in cognition and brain function associated with long term or frequent use of cannabis. Specific impairments of attention, memory, and executive function have been found in cannabis users in the unintoxicated state (and in children exposed to cannabis in utero) in controlled studies using brain event-related electric potential techniques and neuropsychological assessments, including complex tasks. In addition, brain imaging studies of cannabis users have demonstrated altered function, blood flow, and metabolism in prefrontal and cerebellar regions.3) The authors report a multi-site retrospective cross-sectional neuropsychological study conducted in the US between 1997 and 2000, the study involving 102 near-daily cannabis users (51 long-term users; mean, 23.9 years of use; 51 shorter-term users; mean, 10.2 years of use) compared with 33 nonuser controls. The authors report their results confirm that long-term heavy cannabis users show impairments in memory and attention that endure beyond the period of intoxication and worsen with increasing years of regular cannabis use.J. Am. Med. Assoc. http://www.jama.com--------------------------------Related Material:NEUROBIOLOGY: ON MARIJUANA CANNABINOIDSNotes by ScienceWeek:The drug "marijuana" is derived from the hemp plant Cannabis sativa. The parts of the plant vary in potency, the resinous exudate of the flowering tops of the female plant the most potent, providing "hashish" and "charas". Next in potency are the dried leaves and flowering shoots of the female plant (providing "bhang"), and the resinous mass from small leaves of inflorescence (providing "ganja"). The drug is usually inhaled by smoking, with marijuana "joints" containing approximately 500 milligrams of marijuana, which in turn contains approximately 5 to 15 milligrams of tetrahydrocannabinol (THC).With moderate dosage, marijuana produces mild euphoria followed by sleepiness. In the acute state, the user has an altered time perception, less inhibited emotions, psychomotor problems, and impaired immediate memory. High doses produce transient effects resembling psychosis. The drug frequently aggravates existing mental illness, adversely affects motor performance, and slows the learning process in children. Studies of long-term effects have conclusively demonstrated abnormalities in the lungs, laryngitis, rhinitis, and chronic obstructive pulmonary disease. Chronic usage has resulted in depression of plasma testosterone levels and reduced sperm counts. Abnormal menstruation and failure to ovulate have occurred in some female users. Sudden withdrawal produces insomnia, nausea, muscle pain (myalgia), and irritability. In general, marijuana is a potent psychoactive drug acting on the central nervous system and producing both acute and chronic neurophysiological effects.The most important neuroactive chemical ingredients in marijuana are the lipophilic cannabinoids, especially delta-9-tetrahydrocannabinol. Cannabinoids are believed to act at several specific cannabinoid receptors in the brain. When a human inhales or ingests marijuana, the liver transforms it into a number of metabolites, the most important of which is 11-hydroxy-delta-9-tetrahydrocannabinol, which has effects identical to those of the parent compound. 11-hydroxy-delta-9-THC is in turn converted to more polar and inactive metabolites which are excreted in urine.Since certain cannabinoids are already present in the nervous system without input of any drug, cannabinoids need to be categorized as "exogenous" (from outside) versus "endogenous" (from inside).In this context, the term "G-proteins" refers to a family of signal-coupling proteins that act as intermediaries between activated cell receptors and effectors, for example, the transduction of hormonal signals from the cell surface to the cell interior. The G-protein is apparently embedded in the cell membrane with parts exposed on the outside surface and inside surface. The outside moiety is activated by the "first messenger" (e.g., a hormone), and the inside moiety activates a "second messenger", the G-protein thus acting as a trans-membrane signal transducer."Neurotransmitters" are chemical substances released at the terminals of nerve axons in response to the propagation of an impulse to the end of that axon. The neurotransmitter substance diffuses into the synapse, the junction between the presynaptic nerve ending and the postsynaptic neuron, and at the membrane of the postsynaptic neuron the transmitter substance interacts with a receptor. Depending on the type of receptor, the result may be an excitatory or an inhibitory effect on the postsynaptic nerve cell."GABA" is gamma-amino butyric acid, a neurotransmitter substance. The term "GABA receptor" refers to any of several membrane proteins that bind GABA and mediate its effects as an inhibitory neurotransmitter.In this context, the term "depolarization" refers to a reduction in the potential difference across the cell membrane. The neuron action potential involves not only a transient depolarization of the membrane but also a transient reversal of polarity of the potential difference, the potential difference across the neuron membrane during an action potential changing from approximately -60 millivolts (inside negative) to approximately +40 millivolts.The "hippocampus" is a brain cortex structure in the medial part of the temporal lobe. In humans, among other functions, the hippocampus is apparently involved in short-term memory. Analysis of the neurological correlates of learning behavior in the rat indicates that the hippocampus is also involved in memory in that species. Nerve cells in rat brain slices remain active in vitro in appropriate solutions for up to 24 hours, and such slices are convenient tissues for experiments. "Hippocampal pyramidal neurons" are a specific type of nerve cell in the hippocampus.The term "retrograde signaling" refers to neural information transmission in a direction opposite to the primary signal direction. In this context, the term refers to signaling from postsynaptic neuron to presynaptic neuron. In general, retrograde signaling in neural systems is usually part of a negative feedback process.In general, an "interneuron" is any neuron that branches locally to innervate other neurons.In general, in this context, an "agonist" is any substance that binds to and activates a receptor.The following points are made by R.I. Wilson and R.A. Nicoll (Nature 2001 410:588):1) Marijuana affects brain function primarily by activating the G-protein-coupled cannabinoid receptor-1 (CB1), which is genetically expressed throughout the brain at high levels. Two endogenous lipids, anandamide and 2-arachidonylglycerol (2-AG), have been identified as cannabinoid receptor-1 ligands, and depolarized hippocampal neurons have been shown to rapidly release both anandamide and 2-AG in a calcium-dependent manner. In the hippocampus, cannabinoid receptor-1 is expressed mainly by GABA-mediated inhibitory interneurons, where cannabinoid receptor-1 apparently clusters on axon terminals of such interneurons. A synthetic cannabinoid receptor-1 agonist has been demonstrated to depress GABA release from hippocampal slices, which suggests that the function of endogenous cannabinoids released by depolarized hippocampal neurons might be to reduce GABA release (down-regulate GABA release).2) The authors report that their experiments indicate that the transient suppression of GABA-mediated transmission that follows depolarization of hippocampal pyramidal neurons is mediated by retrograde signaling through release of endogenous cannabinoids. Signaling by the endocannabinoid system thus represents a mechanism by which neurons can communicate backwards across synapses to modulate their inputs. The authors suggest this study represents the first identification of a physiological process mediated by endogenous brain cannabinoids. Exogenous cannabinoids such as marijuana may destroy the information contained in endogenous cannabinoid feedback loops and thus promote a more random pattern of synaptic modification.Nature http://www.nature.com/natureScienceWeek http://scienceweek.com http://scienceweek.com/2005/sw050617-5.htm
Marijuana Ingredient Slows Heart Disease 
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