Muscarinic and NMDA receptors in the substantia nigra play a role in reward-related learning.

These results suggest that SN mACh and NMDA receptors are key players in the acquisition, but not the expression of reward-related learning. Importantly, these findings redefine the role of the SN, which has traditionally been known for its involvement in motor processes and suggest that the SN possesses attributes consistent with a function as a hub of integration of primary reward and conditioned stimulus signals.