Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14NIDA NIDA’s mission is to bring the power of science to bear on drug abuse and addiction.Slide 1The National Institute on Drug Abuse (NIDA) is part of the National Institutes of Health and is dedicated to bringing the power of science to bear on drug abuse and addictionWhen a person first thinks about trying drugs, it is usually a voluntary decision. “Maybe I should see what it’s like.., just this once,” you might think. Or a friend dares you. Or you just want to feel good or forget your troubles. Most drugs of abuse—including nicotine, alcohol, marijuana, cocaine, and heroin—activate a part of the brain called the reward system, and that makes you feel good. Drug abuse has serious consequences. The most serious consequence is that prolonged drug use can change the brain in fundamental and long-lasting ways. Eventually, it becomes difficult to derive pleasure from other normal activities, such as sports, food, or sex. After repeated drug use, you reach a point when deciding to use drugs is no longer voluntary. Scientists have proof now that drugs literally change your brain. It’s as if a “switch” goes off in the brain. It is during this transformation process that a drug abuser becomes a drug addict. Addiction is a chronic relapsing disease characterized by compulsive, often uncontrollable, drug seeking and drug use in the face of negative consequences. Drug addicts need professional help andtreatment to help them cope with these changes and possibly change the brain back to normal.Slide 2The brain is the most complex organ in the bodyThe brain is made up of a complex network of billions of nerve cells called neurons, as well as other kinds of cells, all protected by the skull. The typical brain weighs only about 3 pounds, but it is the source of most qualities that make you who you are. Neurons in the brain and spinal cord are part of the nervous system and act as a body’s “Command Central.” The brain is constantly active, even when we are asleep.As a matter of fact, asleep or awake, the brain requires 20percent of the heart’s output of fresh blood and 20 percentof the blood’s oxygen and glucose to keep functioningproperly. Glucose is a type of sugar that is our brain’sprimary fuel. The brain produces enough electrical energy to power a40-watt light bulb for 24 hours. That’s a lot of energy for ahuman organ a little bigger than a softball.Slide 3How a neuron worksNeurons are unique because of their computational prowess that allows them to rapidly process, integrate, and disseminate vast amounts of information within the brain and throughout the body.Your brain communicates with the rest of your body by sending messages from one neuron to the next and ultimately to the muscles and organs of the body. Neurons can also store information, a fundamental property that, when scaled up to the level of whole networks, allows for the creation of memories. Typically, a neuron contains three important parts: a cell body that directs all activities of the neuron; dendrites (the part that looks like tree branches), which are short fibers that receive messages from other neurons and relay those messages to the cell body; and the axon, a long single fiber that transmits messages from the cell body to dendrites of other neurons. Every moment, messages traverse entire neural networks with amazing speed. As a matter of fact, scientists often compare the activity of neurons to the way electricity works.A neuron communicates with other neurons at special places called synapses or synaptic clefts. To send a message, a neuron releases a chemical messenger, or neurotransmitter, into the synaptic cleft. From there, the neurotransmitter crosses the synapse and attaches to key sites called receptorson the receiving neuron. When neurotransmitters attach to these receptors, they cause changes inside the receiving neuron and the message is delivered. Neurons communicate with each other within a network of interconnected cells that scientists are still trying to fully understand. Scientists do know that this complex communication system within the braincan be disrupted by the chemicals in drugs. Did you know that more than 400 chemicals are in a marijuana leaf? And over 4,000 chemicals besides nicotine are in tobacco!Slide 4The brain is your body’s “Command Central”Your brain controls more than the way you think. The braincontrols our physical sensations and body movements.How we understand what we see, hear, smell, taste, andtouch. Our sense of balance and coordination. Memory.Feelings of pleasure and reward. The ability to makejudgments. When we catch a football, dance, jog, speak,sing, laugh, whistle, smile, cry—that’s our brain receiving,processing, and sending out messages to different parts ofour body. When we feel good for whatever reason—laughing with a friend or seeing a good movie or eating our favorite ice cream—the brain’s reward system is activated. As we said before, the reward system is the part of the brain that makes you feel good. The reward system is a collection of neurons that release dopamine, a neurotransmitter. When dopamine is released by these neurons, a person feels pleasure. Scientists have linked dopamine to most drugs of abuse—cocaine, marijuana, heroin, alcohol, and nicotine. These drugs all activate the reward system and cause neurons to release large damaging amounts of dopamine. Over time, drugs change this part of the brain. As a result, things that used to make you feel good—like eating ice cream, skateboarding, or getting a hug—no longer feel as good. Slide 5Control centers in the brain are affected by drug useDrugs of abuse disable or disrupt important brain functions. When someone smokes marijuana, for example, thechemical THC (delta-9-tetrahydrocannabinol), the mainpsychoactive ingredient in marijuana, travels quickly to thebrain. We can see the areas of the brain (in purple) whereTHC concentrates. Let’s go back to the previous slide andsee the areas of the brain that are affected by THC. You can see that THC builds up in areas that control thebody’s movements, balance, coordination, memory andjudgment, and sensations. THC disrupts your brain’s ability to control these activities as well as you could normally. Slide 6A positron emission tomography (PET) scanner Now let’s take a look inside your mind.