Ketamine attenuates habenula activity in response to aversive outcomes during Pavlovian learning.

Ketamine reduces habenula activity during aversive stimuli expectations and outcomes in healthy adults 24 hours after infusion.

• Why it matters: Understanding how ketamine affects habenula function is crucial because this small brain structure plays a key role in aversive learning and depression, yet human evidence is limited.
• What they did: Researchers conducted a randomized, placebo-controlled study with 70 healthy adults, using a Pavlovian conditioning task and 7-tesla fMRI to measure habenula responses after ketamine or placebo.
• The result: Ketamine attenuated habenula responses during aversive stimuli, and reduced habenula activity during learning may lessen negative memories, supporting its rapid antidepressant mechanism.