Nucleus accumbens-presentation


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Nucleus accumbens-presentation

  1. 1. The Nucleus Accumbens <ul><li>By: Nicole, Tobias & Kristine </li></ul>
  2. 2. Where is it located? <ul><li>The nucleus accumbens is located at the base of the forebrain, the largest part of the brain. </li></ul><ul><li>The word accumbent is defined as lying down or leaning against something in a position of comfort. </li></ul>
  3. 3. Description <ul><li>The nucleus accumbens is a brain region involved in functions ranging from motivation and reward to feeding and drug addiction. </li></ul><ul><li>The Nucleus accumbens is typically divided into two major subdivisions, the shell and the core. </li></ul><ul><li>Sometimes called the brain ’s “pleasure center”, this cluster of neurons modulates the effects of the neurotransmitter dopamine, on which many neural circuits depend. </li></ul><ul><li>The nucleus accumbens is a link in the brain pathways that cause addiction and depression. </li></ul>
  4. 4. Connection the Rest of the Brain <ul><li>The major interaction is with the ventral tegmental area ( VTA ) which connects via the mesolimbic pathway </li></ul><ul><li>Dopaminergic input from the VTA activates the Nucleus Accumbens </li></ul><ul><li>Dopamine is a neurotransmitter and it activates the Nucleus Accumbens whenever we feel pleasure </li></ul>
  5. 5. Addiction <ul><li>Lab research points to a relationship between addiction and the release of seratonin and dopamine in the nucleus accumbens. </li></ul><ul><li>The surge of these neurotransmitters triggers neural activity correlating with the addicts’ high and the sensation of reward on which addiction depends. </li></ul><ul><li>When someone craves a substance, neural activity increases in anticipation of future pleasure. </li></ul>
  6. 6. Placebo Effect <ul><li>Nucleus Accumbens is responsible for the expectancy for reward </li></ul><ul><li>When a fake reward is administered, the dopamine is released </li></ul><ul><li>High Dopamine release causes a high and a “good feeling,” which helps heal the body </li></ul>
  7. 7. Research <ul><li>1) Dean Sabatinelli, 2007 </li></ul><ul><ul><li>Pleasure rather than salience activates human nucleus accumbens and medialprefrontal cortex </li></ul></ul><ul><li>2) Mary Kay Lobo, 2010 </li></ul><ul><ul><li>Why Cocaine Is So Addictive: Activation of Specific Neurons Linked to Alterations in Cocaine Reward </li></ul></ul><ul><li>3) Traute Flatscher-Bader, 2010 </li></ul><ul><ul><ul><li>According to researchers from Australia, the connection between nicotine and alcohol addiction may lie in the nucleus accumbens. </li></ul></ul></ul>
  8. 8. Dean Sabatinelli <ul><li>Pleasure rather than salience activates human nucleus accumbens and medial prefrontal cortex </li></ul><ul><li>Free viewing of pleasant images of erotic and romantic couples prompts clear, reliable increases in nucleus accumbens (NAc) and medial prefrontal cortex (mPFC) activity </li></ul><ul><li>However, equally arousing (salient) unpleasantimages, and neutral pictures, do not </li></ul><ul><li>Data suggest that in visual perception, the human NAc and mPFC are specifically reactive to pleasant, rewarding stimuli, and are not engaged during by unpleasant stimuli, despite high stimulus salience. </li></ul><ul><li>(Sabatinelli, 2007) </li></ul>
  9. 9. Mary Kay Lobo <ul><li>Why Cocaine Is So Addictive: Activation of Specific Neurons Linked to Alterations in Cocaine Reward </li></ul><ul><li>Cocaine corrupts the brain and becomes addictive </li></ul><ul><li>Discovered connected activation of specific neurons to alterations in cocaine. The results may help researchers in developing new ways of treating those addicted to the drug. </li></ul><ul><li>Two main neurons (D1 and D2) in the nucleus accumbens region of the brain, exert opposite effects on cocaine reward. </li></ul><ul><ul><li>Activation of D1 neurons increases cocaine reward </li></ul></ul><ul><ul><li>Activation of D2 neurons decreases cocaine reward </li></ul></ul><ul><li>(Lobo, 2010) </li></ul>
  10. 10. Traute Flatscher-Bader <ul><li>According to researchers from Australia, the connection between nicotine and alcohol addiction may lie in a pleasure center in the brain, called the nucleus accumbens, which also plays an important role in addiction. </li></ul><ul><li>Describes an overlap of the effect of alcohol and nicotine in the brain </li></ul><ul><li>Analyzed the expression of thousands of genes in the post-mortem brain tissue of smokers, alcoholics and those who enjoyed both drugs </li></ul><ul><li>Discovered that a specific group of genes expressed in the nucleus accumbens were most active in people who abused both alcohol and nicotine </li></ul><ul><li>When overactive, these genes alter the structure of cells in the nucleus accumbens and may rewire this brain region </li></ul><ul><ul><li>This finding may help us understand why both drugs are often consumed together ; each drug appears to enhance the addictive properties of the other </li></ul></ul><ul><li>Flatscher-Bader, 2010 </li></ul>
  11. 11. Dysfunction of the Nucleus Accumbens <ul><li>Research shows that damage to the Nucleus Accumbens can cause: </li></ul><ul><li>Lack of motivation and inhibits addictive behavior. </li></ul><ul><li>Impulsive choice </li></ul><ul><li>ADHD (attention deficit hyperactivity disorder) </li></ul><ul><li>Tourette syndrome </li></ul>
  12. 12. Thanks for listening 