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18 Cards in this Set
- Front
- Back
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What is common across all drugs of abuse?
(affect which system) (increase levels of what within...) |
They (in)directly affect the dopamine system; all drugs of abuse lead to an increase in dopamine levels within the nucleus accumbens
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In what two ways is opiate addiction different from any other drug addiction?
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Opiate addiction is characterized by TOLERANCE (a user must take increasing amounts to get high) and WITHDRAWAL (physical symptoms upon cessation of the drug).
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What is Korsakoff's Syndrome? Its cause?
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Caused by lack of Thiamine, or vitamin B1.
Linked to chronic alcohol abuse, resulting in neural degeneration of the MAMMILLARY BODIES. Symptom: Severe, permenant memory loss |
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What is FAS? Its cause? What brain abnormality does it cause?
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Fetal Alcohol Syndrome, caused by exposure to alcohol during prenatal development, resulting in mental retardation.
No corpus callosum, less cortical folds (sulci or gyri) |
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What is addiction? Name 2 characteristics.
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1) The recurrent failure to control behavior (powerlessness) and
2) Continuation of the behavior despite its negative consequences (manageability) |
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How is addictive potential measured?
What does addictive potential seem to correspond with in the brain? |
By how quickly a rat learns to press a lever to receive the drug.
Dopamine release in the nucleus accumbens: the higher the addictive potential, the more dopamine is released. |
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Describe the experiment that showed that it's not the pleasurable feeling of a drug that drives addiction.
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Addicts were given a choice between two levers that resulted in self-administration of two unknown substances. In condition where one lever administered placebo and the other a low dose of cocaine, there was a discrepancy between their behavior and their subjective experience; they reported no pleasurable experience of the drug, but they did choose the lever associated with the drug more often.
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How do we know that wanting and liking are different experiences? Which neurotransmitter is associated with each of these experiences?
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Manipulation of dopamine levels in the nucleus accumbens leads to changes in lever pressing (WANTING), whereas manipulation of opioid levels resulted in changes in taste reactivity (LIKING).
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What do we mean by aberrant learning?
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Because drugs of abuse produce a dopamine burst pharmacologically, you never stop learning about the drug, and the desirability of the drug can increase indefinitely. This is in contrast to normal learning, during which the dopamine burst after the reward (e.g. food) disappears after learning what predicts it (e.g. lever press).
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What is the evidence for (cross-)sensitization? What other experience can sensitize the brain to addiction?
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Prior exposure to any drug increases the likelihood of becoming addicted to drugs later in life.
Early life stressors. |
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Alcohol:
System(s) affected, acute effect(s), and chronic effect(s)? |
Systems & Acute effect: NMDA receptors (low dose, stimulant) & GABA receptors (high dose, depressant).
Chronic: Apoptosis, fatality |
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Nicotine:
System(s) affected, acute effect(s), and chronic effect(s)? |
System & acute effect: Cholinergic receptors, stimulant.
Chronic: fatality |
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Marijuana (THC):
System(s) affected, acute effect(s), and chronic effect(s)? |
System & acute effect: Cannabinoid receptors, mixed effects.
Chronic effect: left blank |
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(Crack) Cocaine:
System(s) affected, acute effect(s), and chronic effect(s)? |
System & acute: Dopamine reuptake, stimulant.
Chronic effect: left blank |
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Methamphetamine:
System(s) affected, acute effect(s), and chronic effect(s)? |
Dopamine reuptake, stimulant.
Chronic: Schizophrenia like symptoms (increased cortical dopamine); Parkinson's disease (loss of striatal dopamine neurons) |
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Pain Relievers:
System(s) affected, acute effect(s), and chronic effect(s)? |
Opioid receptors
acute and chronic left blank. |
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How does nicotine affect the brain? To which receptors do nicotine bind, and how does it affect dopamine levels in the nucleus accumbens?
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-Bind to nicotinic ACh receptors (INCREASE ATTENTION and MEMORY)
-It INCREASES dopamine in NAcc |
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Explain how addiction could be the consequence of aberrant learning (due to "high-jacking" of the dopamine system?
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-Normally dopamine pulse predicts reward (tied to cue)
-Drugs ALWAYS provoke dopamine; prediction error says that the drug is more rewarding than expected, therefore constantly reinforcing |
