A role for primate subgenual cingulate cortex in sustaining autonomic arousal

Area of Science:

• Neuroscience
• Affective Science
• Primate Research

Background:

• The subgenual anterior cingulate cortex (subgenual ACC) is implicated in emotional regulation and mood disorders.
• Its specific causal role in positive emotion, particularly sustained positive affect, remains unclear.

Purpose of the Study:

• To investigate the subgenual ACC's contribution to autonomic arousal during anticipation of positive emotional events.
• To understand how this brain region supports sustained positive affect.

Main Methods:

• Utilized Pavlovian conditioning in macaque monkeys to associate cues with rewards.
• Assessed autonomic arousal responses before and after lesions to the subgenual ACC.

Main Results:

• Monkeys with subgenual ACC lesions exhibited initial cue-evoked arousal but failed to sustain it until reward delivery.
• Control experiments ruled out alternative explanations such as impaired reward learning or basic autonomic response deficits.

Conclusions:

• The subgenual ACC is essential for maintaining arousal in anticipation of positive outcomes.
• Impaired sustained positive affect due to subgenual ACC dysfunction may contribute to mood disorders characterized by negative emotional dominance.