Neuroscience MCAT Practice Question
A neurotoxicology study examines a compound that selectively inhibits vesicular monoamine transporter 2 (VMAT2) in dopaminergic neurons. This transporter normally sequesters cytoplasmic dopamine into synaptic vesicles, protecting it from oxidative degradation. VMAT2 inhibition causes dopamine accumulation in the cytoplasm, promoting generation of reactive oxygen species. What cellular consequence results from chronic VMAT2 blockade?
Answer choices
- AEnhanced dopamine synthesis via feedback activation of tyrosine hydroxylase
- BIncreased spontaneous vesicular release due to higher intravesicular dopamine
- CMitochondrial dysfunction and neuronal death from oxidative stressCorrect answer
- DUpregulation of dopamine reuptake transporters (DAT) to compensate
- EEnhanced neuroprotection via increased antioxidant enzyme expression
- FIncreased dopamine efflux through the plasma membrane via reverse operation of the dopamine reuptake transporter (DAT)
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