CARN Neurobiology of Addiction 3 — Questions and Answers
Question 1: Which brain region is most impaired in addiction, contributing to poor impulse control and continued drug use despite negative consequences?
- Occipital cortex
- Prefrontal cortex (Correct answer)
- Brainstem reticular formation
- Primary somatosensory cortex
Correct answer: Prefrontal cortex
Prefrontal cortex dysfunction in addiction impairs executive functions including inhibitory control, decision-making, and the ability to override drug-seeking behavior.
Question 2: Glutamate's role in addiction is most accurately described as:
- Solely inhibitory, reducing drug-seeking behavior
- Mediating neuroplasticity and learning that reinforces drug-seeking habits (Correct answer)
- Only relevant during acute intoxication phases
- Exclusively involved in GABAergic cross-modulation
Correct answer: Mediating neuroplasticity and learning that reinforces drug-seeking habits
Glutamate mediates synaptic plasticity and learning processes that strengthen drug-associated memories and habitual drug-seeking behavior.
Question 3: Kappa-opioid receptor activation is associated with which affective state that contributes to the negative reinforcement cycle of addiction?
- Euphoria and pleasure
- Dysphoria and aversion (Correct answer)
- Sedation and sleep
- Anxiety reduction and calm
Correct answer: Dysphoria and aversion
Kappa-opioid receptor activation produces dysphoria and aversive states, which during withdrawal motivates drug use to escape negative affect (negative reinforcement).
Question 4: The corticotropin-releasing factor (CRF) system's role in addiction primarily involves:
- Increasing dopamine synthesis in the VTA
- Mediating stress-induced relapse and negative emotional states during withdrawal (Correct answer)
- Blocking NMDA receptors during acute intoxication
- Enhancing serotonin reuptake in limbic regions
Correct answer: Mediating stress-induced relapse and negative emotional states during withdrawal
CRF drives the stress response in the extended amygdala and is a key mediator of negative emotional states during withdrawal and stress-induced drug craving and relapse.
Question 5: Long-term potentiation (LTP) in addiction neuroscience is significant because:
- It weakens synaptic connections involved in drug memories
- It strengthens synaptic connections encoding drug-related learning and craving (Correct answer)
- It occurs exclusively in the cerebellum during substance use
- It is blocked by all FDA-approved addiction treatments
Correct answer: It strengthens synaptic connections encoding drug-related learning and craving
LTP strengthens glutamatergic synapses encoding drug-cue associations in regions like the nucleus accumbens and amygdala, making drug memories highly persistent.
Question 6: The 'incentive salience' theory of addiction proposes that compulsive drug seeking is driven by:
- The pleasure derived from drug effects diminishing over time
- Excessive 'wanting' attributed to drug cues, dissociated from actual drug 'liking' (Correct answer)
- GABA receptor downregulation in the hippocampus
- Serotonin depletion in the dorsal raphe nucleus
Correct answer: Excessive 'wanting' attributed to drug cues, dissociated from actual drug 'liking'
Incentive salience theory (Robinson & Berridge) distinguishes 'wanting' (dopamine-mediated craving) from 'liking' (opioid-mediated pleasure), explaining why craving persists despite reduced pleasure.
Question 7: Chronic alcohol use affects GABA-A receptors primarily by causing:
- Upregulation and increased sensitivity to GABA
- Downregulation and decreased sensitivity, leading to tolerance and withdrawal seizure risk (Correct answer)
- No significant change in receptor density or function
- Selective enhancement of benzodiazepine binding sites only
Correct answer: Downregulation and decreased sensitivity, leading to tolerance and withdrawal seizure risk
Chronic alcohol (a GABA-A positive allosteric modulator) causes GABA-A receptor downregulation and reduced sensitivity, creating tolerance and dangerous withdrawal when alcohol is stopped.
CARN Neurobiology of Addiction 3
Which brain region is most impaired in addiction, contributing to poor impulse control and continued drug use despite negative consequences?