Neurobiology of Addiction Flashcards

Stress-induced relapse is neurobiologically mediated primarily through which system projecting to the bed nucleus of the stria terminalis (BNST)?

Answer: CRF and noradrenergic projections from the locus coeruleus and amygdala

Stress-induced relapse involves CRF and noradrenergic (from locus coeruleus) inputs to the BNST and extended amygdala, activating anxiety and drug-seeking circuits.

The 'dark side of addiction' described by Koob refers to:

Answer: The negative emotional state driving drug use for relief rather than pleasure

Koob's 'dark side' describes the shift from positive reinforcement (seeking pleasure) to negative reinforcement (seeking relief from dysphoria, anxiety, and pain) as addiction progresses.

Which receptor type mediates alcohol's positive reinforcing effects through the mesolimbic dopamine system?

Answer: Multiple systems including mu-opioid, GABA-A, and dopamine receptors acting in concert

Alcohol's rewarding effects involve multiple receptor systems: mu-opioid receptors trigger dopamine release, GABA-A activation produces anxiolysis and euphoria, and NMDA blockade contributes to its reinforcing profile.

Nicotine's addictive properties are primarily mediated through its action on:

Answer: Nicotinic acetylcholine receptors (nAChRs) on VTA dopamine neurons

Nicotine directly activates alpha4beta2 nicotinic acetylcholine receptors on VTA dopamine neurons, stimulating dopamine release in the nucleus accumbens and producing reinforcement.

Genetic heritability estimates for substance use disorders generally range from:

Answer: 40-60%, indicating substantial but not deterministic genetic contribution

Twin and family studies consistently estimate heritability of substance use disorders at 40-60%, indicating genes significantly influence vulnerability while environment also plays a major role.

Downregulation of D2 dopamine receptors in the striatum, observed in addiction neuroimaging, contributes to:

Answer: Blunted reward response to natural reinforcers, increasing vulnerability to drug seeking

D2 receptor downregulation reduces sensitivity to natural rewards, creating a hypodopaminergic state where only powerful drug stimuli can generate meaningful reward signals.

The process of extinction learning in addiction treatment (such as cue exposure therapy) targets which neurobiological mechanism?

Answer: Forming a new inhibitory memory that competes with the drug-cue association

Extinction does not erase original drug-cue memories but forms new inhibitory associations in the prefrontal cortex that suppress conditioned responses — explaining why relapse remains possible.