Brain Structure, Neurotransmitters, and Behavior (7A) Practice Test

In a pharmacology experiment, 26 participants received either a selective $5$-$\text{HT}_{2A}$ receptor agonist at a subhallucinogenic dose or placebo before completing a cognitive reappraisal task during fMRI. The agonist increased functional coupling between medial prefrontal cortex (mPFC) and amygdala during reappraisal trials and was associated with greater reduction in negative affect ratings. Which outcome is most consistent with the observed neurotransmitter effects?

In a study of memory consolidation, 27 participants received a $\beta$-adrenergic antagonist before viewing emotionally negative and neutral images. Twenty-four hours later, recognition memory for negative images was selectively reduced in the drug group, while memory for neutral images was similar to placebo. Amygdala activation during encoding of negative images was reduced, but hippocampal activation during neutral encoding was unchanged. Which statement best explains the findings?