Lecture 10 (Exam 1)

Question 1

What is the difference between dependence and addiction?

Answer 1

• Dependence: Persistent use accompanied by tolerance or withdrawal.
• Addiction: A disorder of pathologic decision making, such as, Expression of compulsive destructive behavior despite extreme negative consequences Criminal behavior.

Question 2

What is the ‘Pleasure Pathway’ and what does it have to do with drug addiction?

Answer 2

• Almost all abused substances enhance dopamine (neurotransmitter) activity in the Nucleus Accumbens (Pleasure Pathway), which alter pleasure, motor, and cognitive function. This can also involve the Glutamate (excitatory stimulus) and GABA (inhibitory stimulus) pathways.

Question 3

The Dopamine and Serotonin pathways both affect the same parts of the brain, which three parts are there? Where is Dopamine released from and what effect does this have? Where is Serotonin released from and what does this have an effect on?

Answer 3

• Prefrontal Cortex/Frontal Cortex (problem solving and behavior), Striatum (reward system) and Hippocampus (limbic/emotion systems & short term memory).
• Dopamine: Raphe Nuclei: Functions: Reward (motivation), Pleasure, Euphoria, Motor function (fine tuning), Compulsion, Perseveration, Decision making.
• Serotonin: Substantia Nigra???: Mood, memory, processing, sleep and cognition.

Question 4

What is a synthetic, addictive, mood-altering drug, used illegally as a stimulant and legally as a prescription drug to treat children with ADD and adults with narcolepsy? What affect do these have on the dendrites and synaptic connections?

Answer 4

• Amphetamines

- Amphetamine Alters Dendrites And Increases Synaptic Connections (by 2X).

Question 5

Many drugs cause the RELEASE of Dopamine out of the Nerve Terminal to attach to receptors, drugs such as: opioids/narcotics, nicotine, marijuana, caffeine, alcohol, and sedatives/hypnotics. What effect do each of these have?

Answer 5

• Opioids/narcotics: Activate opioid receptors
• Nicotine: Activate nicotinic receptors
• Marijuana: Activate cannabinoid receptors
• Caffeine: Blocks adenosine receptors
• Alcohol: Activate GABA receptors;
  an inhibitory transmitter
• Sedatives/hypnotics: Activate GABA receptors;
  an inhibitory transmitter

Question 6

What drugs (2) BLOCK the neuronal terminal transporter, which blocks Dopamine from entering into the nerve terminal?

Answer 6

• Cocaine

- Ritalin

Question 7

What drug type cause the RELEASE of Dopamine from the Vesicles and reverse the Transporter and what are some examples?

Answer 7

• Methamphetamines: Amphetamines, MDMA (Ecstasy), Ephedrine, “bath salts”.

Question 8

Substances such as Amphetamines, Cocaine, Nicotine, Ethanol/Alcohol, Sex and Food all have an effect on Dopamine levels. By how much does each of these examples increase Dopamine levels?

Answer 8

• Amphetamines: 10X (most and can cause neurotoxicity)
• Cocaine: 3X
• Nicotine: 2X
• Ethanol/Alcohol: 2X
• Sex: 2X
• Food: 1.5X

Question 9

Expression/Decision Making are all related to these levels of GABA, Glutamate and Dopamine. What are the three main processes in making a decision? Activation of what initiates the behavior tract? What do these processes of decision making have to do with addiction?

Answer 9

• Expression/Decision Making:
  
  • Dominance of Tracts (Dopamine, GABA, Glutamate).
  • Strength of Prefrontal Cortex to Select (override system).
  • Relevance or saliency (orbitofrontal cortex) [Cognition and problem solving].
• Dopamine reward pathway
• The more times the individual takes drugs (increases Dopamine levels) the more stimulation occurs, increasing it’s dominance as a behavior. By doing the opposite (fasting when there is food around), will help to strengthen the ability of the Prefrontal Cortex to make logical decisions.

Question 10

_______ suppresses the expression of DAT (a measure of extrapyramidal Dopamine neurons), long term use of this drug leads to a 4X greater chance of having what mental disease?

Answer 10

• Methamphetamines

- Parkinson’s Disease (compromises motor and cognitive functions).

Question 11

Is there a recovery from dopamine enhancers such as cocaine, meth, alcohol and food addictions?

Answer 11

• After two years, some recovery. However, some functional deficits are permanent.

Question 12

Inheritability (genetic inclination) for Drug Abuse Ranges From what to what? How many Polymorphisms (presence of genetic variation) are associated with drug dependence? When are individuals the most susceptible to drug abuse/addiction and why? What effect does this have? These drug addictions/problems are also associated with mental disorders, why?

Answer 12

• 40-60%
• More than 100 (this means that it’s not just linked to one gene but possibly hundreds).
• Teens/Adolescence (Age 13-26): Impulsive systems develop before the strong cognition is fully developed. (Amygdala [emotion/limbic] develops before the Prefrontal Cortex [thought/cognition]) **(Prefrontal Cortex is the last part of the brain to fully develop)
• If these enhancers are given at a younger age, it becomes much more difficult to kick the habit. *(92% of long-term smokers began before 18 yrs old).
• Drug disorders and mental disorders effect the same areas of the brain.

Question 13

Marijuana is a nonselective drug, what does this mean? What type of receptors does it effect? What can be some side effects from marijuana?

Answer 13

• It means that they are able to effect all parts of the brain.
• Cannabinoid Receptors
• Impaired short-term memory, attention, coordination, learning, sleep problems. Increase bronchitis/cough. Potential addiction (9 percent of users, the number goes up to about 17 percent in those who start using young (in their teens) and to 25 to 50 percent among daily users.), loss of IQ and possible withdrawals.