A mismatch between striatal cholinergic pauses and dopaminergic reward prediction errors
Movement, motivation and reward-related learning depend strongly on striatal dopamine and acetylcholine. These neuromodulators each regulate the other, and disturbances to their coordinated signals contribute to human disorders ranging from Parkinson’s Disease to depression and addiction. Pauses in the firing of cholinergic interneurons (CINs) are thought to coincide with pulses in dopamine release that encode reward prediction errors (RPEs), together shaping synaptic plasticity and thereby learning. However, such models are based upon recordings from unidentified neurons, and do not incorporate the distinct characteristics of striatal subregions. Here we compare the firing of identified, individual CINs to dopamine release as unrestrained rats performed a probabilistic decision-making task. The relationships between CIN spiking, dopamine release, and behavior varied strongly by subregion. In dorsal-lateral striatum a Go! cue evoked burst-pause CIN spiking, quickly followed by a very b