The Mechanisms That Stimulate Dopamine Release in the Brain - Essay Example

Compare and contrast the mechanisms employed by Cocaine, Ecstasy, Heroin, and Cannabis to stimulate dopamine release in the brain and how this relates to their abuse potential. [Name] [Course title] [Course Instructor] [University] Cocaine stimulating dopamine release in the brain Cocaine is considered to be the psychoactive drug that affects the central nervous system. Cocaine is prepared from the leaves of erythroxylon coca bush that is found primarily in the regions of Bolivia and Peru. This drug is considered to be self-administered in several ways. The most common technique of abusing cocaine is through snorting it into powdered form into the nasal sinuses. It can be inhaled alone or with heroin. Cocaine in some countries is sold as hydrochloric acid in the streets in the form of a white crystalline powder called the snow, flake, coke, C, or blow. Cocaine can be a source of a number of psychological effects in human beings, which also includes the stimulation of excess emotional experience. When people take in cocaine they become hyperactive, euphoric and they start talking more than normal and end with experiencing the feeling of extreme alertness and power. This initial high in human beings is then followed by paranoia, depression and severe anxiety that may even lead to addiction. People who get addicted to cocaine may turn this habit to addiction which makes them devoting more time and money for acquiring and using cocaine. Cocaine is considered to be an indirect dopamine of agonist. It works in the large part of the brain by blocking or occupying the transport sites of dopamine in the terminal button present in the neurons of the brain. This causes the prevention in the reuptake of the dopamine by the neuron that released it. This allows high concentration of dopamine to remain in the synapses for a much longer period of time. This high concentration and more than normal presence of dopamine in the synapse can be associated with the high use of cocaine. It can also be associated with several critical functions such as a movement, learning, attention and reinforcing the effect of using cocaine. Therefore the presence of cocaine in high concentrations will be effective in some parts of the brain such as limbic system and basal ganglia. The abuse of cocaine may impose instant euphoric effects on the humans, especially when it is inhaled in the form of smoking. Cocaine exists for a short life time in the brain as well as in the plasma. The half-life of cocaine is about 16 to 87 minutes, when it is administered intravenously. This short life of cocaine causes rapid euphorogenic effect on the human brain. When cocaine is inserted intravenously in the blood it ends up producing hit and run effect on the potentiation of the dopamine’s extracellular levels. When rats are injected with the continuous dose of dopamine intravenously, they may end up experiencing the peak of dopamine level in maximum 10 minutes, which is then followed by the returning back to the regular level after almost 20 to 30 minutes (Anon., 2013). Ecstasy stimulating dopamine release in the brain A drug named Adam, X or Ecstasy has become quite common drug among the teenagers and the adults. Ecstasy is also called MDMA (3, 4-methylenedioxymethamphetamine). It is considered to be a synthetic drug, which may act as both hallucinogenic drug and stimulant increasing the sexual sensations and creating euphoric moods elevation in the humans. It is also the cause of some of the major changes in the level of neurotransmitter present in the brain, such as dopamine and serotonin controlling the behaviors and moods (Kyin, 2013). Dopamine and serotonin are considered to be chemical mediators that are discharged in the synaptic gap present in the neurons. These neurotransmitters present in the brain excite the neuron’s post synaptic membrane allowing millions of the neurons to communicate with one another. Serotonin is the central neurotransmitter, which is discharged from the mid region of the brain where the thalamus-hypothalamus and cerebral hemisphere are linked to the spinal cord. Serotonin receptor exists mostly in the central nervous system and smooth muscles. Serotonin present in the body is responsible for regulating sleep, mood, etc. Amphetamine (such as MDMA) is responsible for causing the discharge of serotonin that creates a heightened sensory experience for the drug users. The people consuming drugs have reported the sensation of distorted and sometimes enhanced sensory perception. This happens because MDMA acts on three pathways of the neurotransmitters, where one of the pathways is the serotoninergic pathways that are responsible for the pronounced effect in behavior, moods, eating habits, sexual function and sleeping. The result of animal experimentation suggests people who intake large amount of ecstasy are at a risk of persistently low formation of serotonin that can be linked to anxiety and depression. The regular users of ecstasy are at an increased risk of developing psychological problems. Heroin stimulating dopamine release in the brain Experiments suggest that heroine injected intravenously may cause extremely unpleasant experience for the users and it may also cause nausea or vomiting. This experience is enough to scare the people taking heroine but the psychological and social pressure experienced by heroin addicts or users may motivate them to use it again. After using heroin a few times the effects of it becomes obvious. Some users have differentiated between “high” and “rush”. The rush last for almost two minutes after the heroine has been injected and paths in the brain before getting distributed in the blood stream converting into the more usable form of morphine (Singer, 2004). Heroine decreases the dopamine level of the brain which helps the addicts in losing the effects of euphoria. They use heroine only to get relief of their unpleasant symptoms. Heroin is the kind of drug that has the most classic withdrawal symptoms. Almost 12 hours after the last dose of heroin taken by the addicts, it experience the symptoms of flue such as weakness, sneezing. In some cases the addict also suffers from depression, nausea, vomiting, muscle cramps and diarrhea (Sherman, 2007). Cannabis stimulating dopamine release in the brain Research suggests that cannabinoids that are considered to be the active constituents of marijuana do not increase the dopamine level as other drugs. This research however was dismissed because accurate and abundant evidence was found about the fact that THC (a type of cannabinoids) may temporary increase the level of dopamine. The rise in dopamine is usually mediated by the CB1 receptors, which occur in the nucleus accumbens one of the regions of the brain. Scientists do believe that increase in the level of dopamine in the nucleus accumbens may reinforce the characteristics of the known drugs. Cannabis withdrawal occurs when a person resists from taking the drug for almost a year. In such case the level of dopamine fall below the normal level which causes negative emotional state in cannabis users. Comparing the effect on dopamine level by all drugs Research suggests that the prolonged use of drugs such as heroine, cannabis, ecstasy and cocaine may decrease the production of dopamine. Cocaine however causes abundance of discharge of dopamine that stays in between the nerve cells for a particular time period. THC, which is an important ingredient of cannabis is mildly hallucinogenic and interacts with the pathways of the brain causing the increased formation of dopamine. However heroin cause the inhibition of dopamine which helps the users to get relief from the unpleasant experiences of life. The effects of all these drugs on dopamine are not same. Cannabis is not a stimulant or a relaxant, while cocaine on the other hand gives the sense of wellbeing to the person. Most of the drugs affect the sensory perception of the user. Cannabis decreased the level of balance and co-ordination in a person whereas people use cocaine and heroin to increase the level of confidence in a particular situation. Cannabis increases the heart rate and lowers the blood pressure whereas heroin, ecstasy and cocaine increase the blood pressure of the person. Drugs like ecstasy and cannabis send a person into a quite mood while heroin and cocaine elevate the depress mood in a person. All the drugs usually increase the urge of sleep in the users causing restlessness, hallucination and psychosis. Cannabis increases the appetite of a person whereas cocaine reduces the appetite of a person. Bibliography Anon., 2013. Cocaine in your brain. [Online] Available at: http://www.macalester.edu/academics/psychology/whathap/ubnrp/dopamine/cocaine.html [Accessed 15 April 2014]. Kyin, M., 2013. Ecstasy. [Online] Available at: http://serendip.brynmawr.edu/bb/neuro/neuro98/202s98-paper1/Kyin.html [Accessed 15 April 2014]. Sherman, C., 2007. Impacts of Drugs on Neurotransmission. [Online] Available at: http://www.drugabuse.gov/news-events/nida-notes/2007/10/impacts-drugs-neurotransmission [Accessed 16 April 2014]. Singer, A., 2004. On Heroin. [Online] Available at: http://serendip.brynmawr.edu/bb/neuro/neuro04/web2/asinger.html [Accessed 16 April 2014]. Read More