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**__THE BRAIN: Analyzing Neurobiology Through the Study of Addiction__** **Big Picture** Specific brain regions control specific brain functions The nervous system communicates by convey information using electrical and chemical signals across synaptic junctions Drugs affect the biochemistry of the synaptic junctions in the reward system The most effective treatment of drug addiction is a controversial issue between the ‘disease-based’ and ‘behavioral-based’ schools of thought. Drug addiction can never be cured (or can it?) **Essential Questions** 1. Should all drug addicts be treated as criminals? 2. What is the best way to treat drug addiction? 3. What separates legal and illegal drugs? 4. Why do some consider dopamine the most influential chemical in the body? ** __Objectives__ ** __**The Brain: What’s Going On in There?**__ 1. _ Examine and analyze the structure of a sheep’s brain and identify the specific regions associated with different functions

2. _ Compare the major regions of the sheep brain with the human brain The main difference of the sheep's brain from the human brain is that the cerebellum of the sheep is proportionately larger than that of the cerbellum in the human brain. The cerebellum of the human brain is located on the bottom, and the spinal chord extends downward from it. The cerebellum of the sheep is located at the back of the brain. There is also a difference in the size of the pituitary gland of the two brains. The cerebral cortex is also far more developed in the human brain, most noteably the prefrontal cortex.

3. _ Analyze PET Scans to determine the different areas associated with different activates, and explain that particular functions are localized to specific areas of the brain

4. _ Describe how brain-imaging techniques allow scientists to study activity in the brain and localize the areas for specific activities Computerized brain imaging technologies now measure and display the variations in chemical composition, blood-flow patterns, and electromagnetic fields that occur in normal and/or abnormal brains. Each of the several current forms of brain imaging technology has strengths and weaknesses, and new developments are continually making the technology faster, more powerful, less invasive, and less expensive. Imaging technology was primarily used in medical diagnosis initially, but it is being increasingly used in pure neuroscience and psychological research. The various computerized imaging technologies differ, but the following analogy demonstrates how someone can examine internal differences in something (a brain) that has a protective cover (a skull): Imagine that you’re looking for similarities, differences, and imperfections in successive slices of a thinly sliced apple or potato. A brain-imaging machine is basically a camera that can rapidly and successively change its focus as it photographs and digitally stores successive thin //slices// of a brain in order to create a comprehensive three-dimensional image of selected properties of the entire brain.

5. _ Identify the reward system of the brain The reward system contains a collection of brain structures which attempts to regulate and control behavior by inducing pleasurable effects. It contains, in order from start to finish, the Ventral Tegmental Area (VTA), the Nucleus Accumbens (NA), and the Prefrontal Cortex. The VTA consists of dopamine, GABA, and glutamate neurons which are activated when a pleasurable activity is done. The neurotransmitter (NT) that was sent by the neuron in the VTA then travels to the NA, where the NT helps modulate the activity of neurons in the VTA. The NT is finally released in to the prefrontal cortex where it produces and controls the pleasurable thoughts and actions of the brain and then the body.

6. _ Recognize that normal behaviors can activate the reward system in the brain and that drugs of abuse affect those same reward circuits the reward system in the brain was created to reward actions that contributed to the survival of the individual. Eating, exercising, mating, etc. are some of the actions that cause the VTA (Ventral Tegmental Area) and NA (Nucleus Accumbens). These actions must be rewarded because animals of lower intelect will not realize that these actions are postive and might not perform them. However, drugs of abuse are designed to act at the same systems that reward for survival actions, thus making them very addictive.

7. _ Explain the contrasting roles of the ‘old brain’ and ‘new brain’ Old Brian - Limbic system/brain stem, midbrain (id) deals with emotions and motivations. The midbrain is a motor relay center it controls many important functions such as the visual and auditory systems as well as eye movement. Portions of the midbrain called the red nucleus and the substantia nigra are involved in the control of body movement. New Brian - Cerebral cortex (Super Ego) deals with societal norms, modifies the actions of the limbic system. The limbic system uses memories, information on how your body is working and current sensory input to generate emotional responses to situations. It is involved with dead, anger and survival. The limbic system also regulates feelings of pleasure related to survival and biological drives such as eating, sex, sleep, and drink. __**Neurons and synapse: The Art of Communication**__ 8. _ Explain the hierarchical organization of the brain, neuron and synapse

9. _ Relate the structure of a neuron to its function A neuron is made up of the soma (cell body), the axon, the myelin sheath, the dendrites, and the terminal buttons. Each of these parts are designed to help the neuron perform it's function. The functions of the neuron include processing, sending, and transmitting chemical messages by action potentials. Dendrites are the end of the neuron that receive chemical messages. This is where the neuotransmitters, that are in the synaptic space, bind to. There are multiple dendrites that branch out which makes it easy for muliple bindings to take place. Also, since they branch out, it is easier for the neurotransmitters to bind to the receptors. The soma is resposible for containing the nucleus, a nucleolus, and cytoplasm. The axon is a very long projection that is responsible for taking electrical impulses away from the soma and dendrites. To make this easier, the axon is covered in a myelin sheath. This myelin sheath insulates the axon and it helps increase the rate of the signals being transmitted. Between the myelin sheath are the nodes of ranvier. At the end of the neuron are the terminal buttons. These terminal buttons have vesicles that contain neurotransmitters. When an action potential is sent down the axon, it reaches the terminal button which will give an impulse to release the neurotransmitters through the terminal membrane and into the synaptic space.

10._Sequence the series of events that allow the transmission of a nerve impulse at the synapse Neurons communicate using electrical signals and chemical messages. Electrical signals cannot cross the synaptic space so an electrical signal triggers chemical changes that can cross to affect the post synaptic neuron. When an electrical signal reaches the pre synaptic axon terminal, membranous sacs called vesicles, filled with chemical compounds, called nuerotransmitters, move toward the membrane of the axon terminal. There they fuse with the membrane and release their contents in the synaptic space. They drift across the synaptic cleft and bind to special proteins called receptors. The binding causes a change in the post synaptic neuron that causes it to generate an electrical impulse that then moves away toward the cell body. The nuerotransmitters are then re uptaked into the pre synaptic neuron to be put into the vesicles. If they are not re uptaked they are broken down by enzymes that are present in the synaptic space. That is the series of events that allow the transmission of a nerve impulse at the synapse.

11. _Describe how of inhibitory and excitatory neurotransmitters can influence nerve transmission at the synapse of neurons in series. Inhibitory and excitatory neurotransmitters affect the synpase by either slowing down its processes or making them faster. Inhibitory neurontransmitters allow less neurons to be released, slower nerve transmission, and therefore, less of the specific chemical (from what we studied, usually dopamine). Excitatory neurotransmitters allow more neurons to be released and therefore, more dopamine. The main inhibitory neuron is GABA and the main excitatory neuron is glutamate. Also, once drugs get involved at the synapse the whole process of what inhibitory and excitatory neurotransmitters do becomes more complex.

__**Drugs: A New Form of Communication**__ 12. _Identify how drugs of abuse will interfere selectively with the neurotransmission at the synapse Drugs can interfere with specific neurotransmitters because their molecules are similiar shapes. Cocaine can interfere by with dopamine by fitting into the transporter proteins that was meant for he dopamine. They can also create the same affects as some NTs because they can fit into the specific receptors thus creating in greater intensity the affect that that NT would have. they can also fit into receptors and block specific NTs from being able to have there affect.

13. _Explain how the route of administration and dosage of a drug determines its effect There are four common routes a drug can be taken into the body. These include inhalation, injection, snorting/snuffing, and ingestion. A drug user achieves the fastest high through inhalation because the drug enters the lungs immediately. But when a drug is inhaled the high does not last as long as other methods. This is because it enters the bloodstream very quickly and thus reaches the liver and is broken down faster. Another reason why a high from inhalation is shortlived is because the drug has to cross a mucous membrane. When a drug is injected it takes longer to reach the brain because it has to travel through the entire bloodstream first. It is very potent though because there is no membrane to cross. The duration of aninjected drug is also shortlived becasue like an inhaled drug it quickly reaches the kidneys and is broken down. When a drug is snorted or snuffed it takes longer to reach its full effect and is not as potent as other methods. This is because the drug can get caught in the mucous and in the lungs. The duration of a snorted/snuffed drug is longer than other methods because it takes awhile to reach the bloodstream. When a drug is ingested it needs to be digested before it takes its effect. This causes the effect to be less potent but longer lasting than other methods.

14. _Design an experiment, and collect data to investigate the effect of caffeine on heart rate. Caffeine is a part of the xanthine group, which makes it a stimulant. When ingested, caffeine binds to the adenosine receptors, because it has a very similar composition to the natural neurotransmitter adenosine. Adenosine is a natural sedative,that is important for deep restful sleep, and calming or decreasing the heart rate. Caffeine works as an inhibitor for adenosine, and consequently increases the impulses in the post synaptic neuron, therefore increasing alertness and heart rate, while decreasing tiredness. Caffeine also increases epinephrine release, which stimulates your sympathetic nervous system which is responsible for the fight or flight response. This neurotransmitter release yields a higher heart rate, similar to when you feel nervous or anxious in a given situationdue to your need for an increase in adrenaline an "adrenaline rush". Studies have shown, that caffeine significantly reduces the risk of heart disease, by increasing the number of cAMP (epinephrine-like) cells that travel to the heart and activate a protein kinase, but this was only proven in case studies that were not severely hypertensive. Another study has proven that race pace endurance has increased by 44% compared to a control group. http://en.wikipedia.org/wiki/Caffeine 15. _Analyze experimental data and show how experimental data can lead to further investigations

__**Drug Abuse and Addiction**__ 16. _Explain how drug abuse, withdrawal and tolerance are related to drug abuse

17. _Distinguish between drug abuse and drug addiction Drug Abuse involves a choice. It is a voluntary action. Drug Addiction is when it no longer is an voluntary action but becomes involuntary and essential for the person's homeostasis. The time when drug abuse becomes drug addiction is different for different people. Everyone has different risk factors that make them more prone to drug addiction such as genetics, famoly structure and influence, peer pressure, age when abuse started, the context of the abuse and coping mechanisms. Addiction usually does not occur after one episode but after many. The way people use drugs is important in determing when drug abuse becomes drug addiction. Medical use of drugs is the use of drugs to help move on with life. Addictive use of drugs is the use of drugs to get away from life.

18._Explain the long-term physical and functional changes in the brain associated with drug abuse and addiction


 * Alcohol**-kills neurons, increases impulses, effects mammillary bodies which decreases memory and kills cortex cells.

meth-damage to dopamine and serotonin (more) producing cells. MDMA (XTC) - damages serotonin releasing neurons -changes activities of areas concerned with cognition, emotion and motor function.
 * Amp/meth**-(release NT. and block reuptake)

LSD: Long lasting psychosis-distortion and disorganization, inability, to reccognize reality -dramatic mood swings -flashbacks
 * Hallucigens**-(block receptors for serotonin)

-damages hippocampus so decrease in short term memory tasks
 * THC**- change in function of neurons in lots of areas of brain and changes behavior

-opiate receptors become less efficient in activating cell messangers so decrease in the effect -major withdrawal symptoms 24- 48 hours afterward
 * Heroin**-(increases impulses)

- decrease receptors for dopamine -> less intense effect -decrease release of dopamine in NA -> decreases cocaines stimulatory effect -Cocaine makes user more sensitive to anaesthetic and convulsant effects of cocaine resulting with death and lower dose -brain of cocaine user is still less active after 100 days of taking it
 * Cocaine**- (block reuptake channels)

19. _Recognize that addiction is influenced by the social and behavioral context of drug abuse 20. _Analyze experimental data to identify the transition between drug addiction and drug abuse 21. _Model the theoretical activity of drug users and determine how risk factors, choice and peer pressure may influence addiction Risk factors, choice, and peer pressure influence drug addiction in many ways. There are many risk factors involved with influencing addiction such as environment, genetics, context of original drug abuse, and peer pressure. The more risk factors that are present, the more likely a person is to become an addict. That is especially true in certain stages of earlier development. Choice also plays a huge role in addiction being that it is that person's choice whether or not they do drugs or not. A person can't become addicted to a certain drug if they choose not to use it. Choice goes along well with will power. Finally, peer pressure can also heavily influence addiction. If a person's peers are all taking a certain drug around that person, he or she might feel obligated to also use the drug in order to fit in. That person might also be ridiculed for not using the drug so he or she uses the drug to fit in and stop the embarrassment of being made fun of and looked down on by others.

22. _Explain how environmental, behavioral and social factors influence drug abuse and addiction The influence of the home environment is usually most important in childhood. Parents or older family members who abuse alcohol or drugs, or who engage in criminal behavior, can increase children's risks of developing their own drug problems. Friends and acquaintances have the greatest influence during adolescence. Drug-abusing peers can sway even those without risk factors to try drugs for the first time. Academic failure or poor social skills can put a child further at risk for drug abuse.The genes that people are born with––in combination with environmental influences––account for about half of their addiction vulnerability. Additionally, gender, ethnicity, and the presence of other mental disorders may influence risk for drug abuse and addiction. http://www.drugabuse.gov/infofacts/understand.html  23. _Explain the difference between acute and chronic diseases and relate to drug abuse and addiction An **Acute illness** typically will "run its course" regardless of whether or not there is drug intervention. Coughs, colds, teething, PMS, sleeplessness are all examples of such illnesses. Usually, medicines for acute illnesses are regulated as OTC (over-the-counter) drugs. A **Chronic illness** is one that requires medical supervision and is often a disease that has formed over a long period of time. Examples of chronic illnesses are Cancer, AIDS, Kidney Disease and Diabetes. Usually, medicines for chronic illnesses are regulated as Prescription Only. In regards to drug use: one is a drug abuser would be considered to have an acute illness. Where as, a drug addict has a chronic disease. [|http://www.hylands.com/faq/faq5.php
 * __Where Do We Go From Here?__**

24. _Compare the treatment of addiction with other chronic diseases such as diabetes and hypertension More than sixty percent of drug addicts have success treating their disease where as less than thirty percent of people with hypertension and less than 50 percent of people with diabetes have success. The success of drug addicts in dealing with their disease is due to a number of reasons. Drug addicts have positive reinforcement in many ways. For example they start getting friends back, they are able to have a job. Programs are made to be user friendly. There are also rehab centers for the drug addicts to go to for help. A majority of the addicts that are trying to overcome the disease are the ones that actively seek help. It is also easier to remove the temptation. Drug addicts don't see people shooting up or doing their drug of choice on a daily basis unless they put themselves in that situation. For diabetes and hypertension you will always be around the temptations and the unhealthy food. Drug addicts also know they are in more immediate danger. Some drug addicts know if they do their drug of choice one more time they are at high risk of dying. For the most part, hypertension and diabetes are diseases that are life threatening later down the line. Drug addicts are more likely to have a family that is supporting them in trying to get rid of their bad habits. Someone with hypertension is less likely to have a family trying to keep them away from unhealthy food. People with hypertension and diabetes will not have their lives ruined by not sticking to their treatment plan. Drug addicts, however, can lose their job, friends, family, and life almost immediately so they have more at risk. 25. _Explain the effects of methadone and naltrexone on heroin addiction Methadone is a agonist that helps ween heroin addicts off heroin. Agonists are chemicals that bind to a specific receptor to draw out a response such as an inhibition or excitation from an action potential. Methadone binds to opiate receptors as heroine does, but methadone does not produce euphoric effects on the same level as heroin. Methadone helps suppress cravings and withdrawal symptoms from heroin addicts so they can be slowly weened off the drug. Naltrexone is an antagonist that binds to a receptor and blocks it by preventing any other chemicals to bind to the receptor. Naltrexone specifically binds to opiate receptors and blocks it by not allowing any heroin to bind. Using naltrexone is essentially going cold turkey for drug addicts. When taking naltrexone, heroin will not have an effect because the opiate receptors will be blocked. If drug addicts are on naltrexone and decide to take heroin, it is easy to overdose because they will not feel any effects, therefore they will keep taking heroin until they feel the effects which can lead to an overdose. 26. _**D**escribe the most frequent attributes and principles of any drug treatment program

Treament differs from institution depending on their view on the nominal status of what a drug addict is. Most institutions see drugs as a disease. As a disease, the drug addict is expected to go through a predicted set of stages that determines how the treatment will be administered.

A disease is:
 * 1) **Predictable** -- A doctor can effectively predict the stages of drug addiction.
 * 2) **Progression** -- As the drug addict continues using brain altering substances, the disease progresses into different stages.
 * 3) **Chronic** -- The drug addiction is reoccuring and cannot be cured.
 * 4) **Treatable** -- Can a doctor prescribe certain drugs/routines to help reduce the effects of addiction.
 * 5) **Potentially life threatening** -- Is the addiction potentially life threatening (Yes, overdose is a possibility).

Different factors go into how the treatment will be given.
 * Motivation - Does the patient have the willingness and motivation to face the negative aspects of drug addiction.

27. _Examine the stories of different drug addicts and describe the consequences of their actions

**Assessments** Assessments will include….. ID of the different parts of the brain Illustrate the general action of neurotransmitters at the synapse Illustrate the actions of common drugs on the synapse Investigation report on effects of caffeine Write a position paper to support a judge’s decision to place a habitual drug offender in a treatment program rather than jail. Answering the essential questions either verbally or in writing Counsel a drug user on how to overcome their addiction Unit Evaluation