Neurobiology of Addiction Flashcards

Which neurotransmitter is primarily responsible for the reinforcing effects of addictive substances in the mesolimbic pathway?

Answer: Dopamine

Dopamine release in the nucleus accumbens via the mesolimbic pathway mediates the rewarding and reinforcing effects of addictive substances.

The ventral tegmental area (VTA) sends dopaminergic projections to which structure most critically involved in drug reward?

Answer: Nucleus accumbens

The VTA projects dopaminergic neurons to the nucleus accumbens (NAc), forming the mesolimbic pathway central to reward and addiction.

Neuroadaptation to chronic opioid use leads to upregulation of which intracellular signaling pathway, contributing to tolerance?

Answer: PKA/cAMP pathway

Chronic opioid exposure causes upregulation of the adenylyl cyclase/cAMP/PKA pathway (cAMP superactivation), which underlies tolerance and withdrawal symptoms.

Which brain region is most associated with drug-cue conditioned responses and craving triggered by environmental stimuli?

Answer: Amygdala

The amygdala encodes emotional memories associated with drug use and mediates conditioned responses to drug-related cues that trigger craving.

Delta FosB accumulation in the nucleus accumbens after repeated drug exposure is significant because it:

Answer: Acts as a long-lasting transcription factor increasing addiction vulnerability

Delta FosB is a stable transcription factor that accumulates with repeated drug exposure and persistently alters gene expression, increasing addiction vulnerability.

The endogenous opioid system's role in addiction is best described as:

Answer: Modulating pain, reward, and stress responses through mu, kappa, and delta receptors

Endogenous opioids (endorphins, enkephalins, dynorphins) act on mu, kappa, and delta receptors to modulate pain, reward, and stress — all critical components of addiction.

Allostasis in addiction refers to:

Answer: Maintaining stability through change, often resulting in a new, dysregulated set point

Allostasis involves achieving stability through adaptive changes; in addiction, this creates a dysregulated emotional set point requiring drug use to feel 'normal.'