A cholinergic hub in the nucleus accumbens gates opioid-reward learning.

Blocking cholinergic interneurons in the nucleus accumbens prevents morphine-conditioned place preference without affecting dopamine increases in mice.

• Why it matters: Dissociating beneficial and maladaptive opioid effects is challenging because dopamine signaling influences both, highlighting the need to understand specific neural mechanisms involved in opioid-reward learning.
• What they did: Researchers developed naloxone DART, a cell-type-specific opioid receptor antagonist, and delivered it to genetically defined accumbal cholinergic interneurons in mice, observing effects on reward learning.
• The result: Blocking these cholinergic interneurons abolished morphine-conditioned place preference while preserving dopamine responses and acute analgesia, suggesting a cholinergic gate that could inform strategies to limit reward learning without impairing analgesia.