Acetylcholine Sparks Habit Change in Mice, New Study Finds

A mouse study links the neurotransmitter acetylcholine to behavioral flexibility when rewards change: higher acetylcholine release accompanies mice adjusting choices (lose-shift) and exploring new tactics, while blocking its production makes them more rigid. The findings suggest acetylcholine helps break habits and could inform treatments for neuropsychiatric conditions, though behavior results from multiple brain systems, not a single transmitter.