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Biology 202
2002 Third Paper
On Serendip

Neurobiological Effects of Medicinal Marijuana

Alisa Alexander

After conducting extensive research on the different neurobiological effects of medicinal and recreational marijuana, my original question concerning the difference of its effects were still left unanswered. I realized that through discovering the components found in marijuana, logical conclusions could possibly be made answering my original question about the neurological effects of medicinal marijuana verses recreational marijuana. Almost all of the studies conducted about marijuana neglect to address the issue I chose to present in this paper. The sites found give extensive research of the plant, Cannibus Sativa, and active component of the plant, THC. Questions of THC and the effects of this component became the focus of my research which I concluded would lead to the answers I originally sought in my previous paper.

THC, delta-9 tetrahydrocannibinol, is the chemical in the marijuana plant that produces the various effects of the drug. THC is produced in the epidermal glands of the leaves, stems, and the bracts that support the flowers of the marijuana plant. (1) The strength of this element in the plant depends on the different conditions the plant is subjected under. Various climate changes change the degree of effectiveness of THC such as humidity, temperature and sunlight. THC has been proven to affect the transferring of pain in the brain and that it "interacts with the brain's endogenous opioid system, an important system for the medical treatment of pain. (2) THC is absorbed by receptors in the brain that interact with the element, causing the body and mind to react in various ways. There are two types of receptors in the brain that play a role in the effects of marijuana.
CB1, CB2 and anandamide, a substance naturally produced by the body that acts at the cannabinoid receptor and has effects similar to those of THC. The CB1 receptor is found primarily in the brain and mediates the psychological effects of THC. The CB2 receptor is associated with the immune system; its role remains unclear. (2)

THC and other cannabinoids found in marijuana have been found to affect the control of pain, movement and memory. Most of the experiments conducted concerning marijuana have been done on animals and through the research, scientists were able to discover that there is a dependency and withdrawal effect from the use of marijuana but not nearly as sever with other drugs.

The experiments conducted of the drug have been done to differentiate the effects of the two different types of THC and its affects on the brain. Delta-8 and Delta-9 are the two types of THC that produce the neurobiological and psychological effects of marijuana. (3) Delta-9 is much more abundant in marijuana than delta-8 which is why more studies have been conducted regarding the substance. It has also been concluded that since there is more of delta-9 THC, the effects of the drug is largely due to delta-9. When delta-9 THC is inhaled, it reacts with the receptor which then affects the neurons in the brain. The effects in the brain only take place after it binds with the receptors. Binding to a receptor triggers an event or a series of events in the cell that results in a change in the cell's activity, its gene regulation, or the signals that it sends to neighboring cells. (4) Another key tool involves identifying the receptor protein and determining how it works. Which this key information, scientists are able to locate where the components of marijuana effects the receptors in the brain. Signals are sent to the receptors to make them visible once binding has occurred. This is how scientists are able to see where the drug binds to the receptors, which will lead them to where the drug has its greatest effects in the brain. Because THC is mostly a fatty substance, it is easily absorbed by cell membranes therefore entering into the blood faster. (4) Through this process, tracing THC's activity becomes clearly visible.

When marijuana is taken at a specific dosages, in a monitored environment, subjects suffering form various illnesses have be noted to benefit from the drug. Most patients seek marijuana to elevate the pain. THC binding with particular receptors effects nerves that are affected due to certain illnesses. Recent research has made it clear that CB1 receptor agonists act on pathways that partially overlap with those activated by opioids but through pharmacologically distinct mechanisms. (5) Research on cannabinoid biology offers new insights into clinical use, especially given the scarcity of clinical studies that adequately evaluate the medical value of marijuana. For example, despite the scarcity of substantive clinical data, basic science has made it clear that cannabinoids can affect pain transmission and, specifically, that cannabinoids interact with the brain's endogenous opioid system, an important system for the medical treatment of pain. (2)

Institutions nationally have conducted studies on the use of medicinal marijuana on disease stricken patients. The Institute of Medicine published a journal on the use of marijuana and the effects it as a recreational drug and medicinal drug. Because the substance, when used medicinally, is monitored/controlled, the psychological effects on the patient is slightly different, and its effects also vary depending on the type of the disease the patient is suffering from. A complete report done by the National Academy of Sciences details the psychological effects of recreational and medicinal marijuana. In the 20th century, marijuana has been used more for its euphoric effects than as a medicine. Its psychological and behavioral effects have concerned public officials since the drug first appeared in the southwestern and southern states during the first two decades of the century. (6)

When marijuana is taken without regulation of the intake, the effects are quite similar. Those taking the drug, whether recreationally or medicinally experience similar effects. Marijuana has been linked to psychological dependence but not proven to be physically addictive.
"Many users describe two phases of marijuana intoxication: initial stimulation, giddiness and euphoria, followed by sedation and pleasant tranquility. Mood changes are often accompanied by altered perceptions of time and space and of one's bodily dimensions. The thinking process becomes disrupted by fragmented ideas and memories. Many users report increased appetite, heightened sensory awareness and pleasure. Negative effects can include confusion, acute panic reactions, anxiety attacks, fear, and a sense of helplessness and loss of self-control." (7)

Some researchers conclude that constant recreational use of marijuana in high doses can cause lung cancer, respiratory problems and brain impairment. Those advocating the use of medicinal marijuana argue that because it will be controlled by the doctor administering the drug, there isn't a chance of psychological addiction or any other problems believed to be connected with marijuana use.

The main difference between medicinal marijuana and recreational marijuana is the quality of the drug. (8) Purchasing recreational marijuana can subject the user to various side effects due to the purity of the product. Because marijuana is an illegal drug, products sold outside government regulation are subjected to various types of additives to just for profit. These additives can cause serious side-effect in the brain. Because much research on marijuana and the effects of THC on the brain have been conducted, medicinal marijuana is provided in a controlled environment and the product given is of the highest quality. The controlled environment includes careful monitoring of the substance.

Because patients are already suffering from illness such as those listed below, the neurobiological effects, through studies conducted of these patients, have only served to help them.
AIDS. Marijuana can reduce the nausea, vomiting, and loss of appetite caused by the ailment itself and by various AIDS medications. (8)

Glaucoma. Marijuana can reduce intraocular pressure, thereby alleviating the pain and slowing -- and sometimes stopping -- the progress of the condition. (8)

Cancer. Marijuana can stimulate the appetite and alleviate nausea and vomiting, which are common side effects of chemotherapy treatment. (8)

Multiple Sclerosis. Marijuana can limit the muscle pain and spasticity caused by the disease, as well as relieving tremor and unsteadiness of gait. (8)

Epilepsy. Marijuana can prevent epileptic seizures in some patients. (8)

Chronic Pain. Marijuana can alleviate the chronic, often debilitating pain caused by myriad disorders and injuries. (8)

The positive affects of medicinal marijuana documented through the case studies done of patients who used the drug as treatment to help elevate the pain and other side effects due to their illness. THC fast absorption into the blood stream leads to the immediate relief sought by the sick. Research has only concluded that medicinal marijuana because of its pure content and type of subject receiving the drug creates the difference from recreational marijuana use. Only long-term research can show concrete long-term effects of marijuana use. The short-term usage of the drug is helping many cope with their illness, it is because of these effects doctors, patients, and medicinal marijuana supporters rally for legal use of the drug in America. Many who rally for legal use of the drug do so because the statistics fail to prove any long-term psychological effects even when used recreationally.


1)National Academy Press
2)National Academy Press
3)National Academy Press
4)National Academy Press
5)National Academy Press
6)National Academy Press
7)The Effects of Marijuana
8)Medical Marijuana Briefing Paper

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