Drug-induced dopamine release in the NAcc shell and NAcc core is usually not prone to habituation (i.e., the development of drug tolerance: a decrease in dopamine release from future drug exposure as a result of repeated drug exposure); on the contrary, repeated exposure to drugs that induce dopamine release in the NAcc shell and core typically results in sensitization (i.e., the amount of dopamine that is released in the NAcc from future drug exposure increases as a result of repeated drug exposure).