Specifications include, but are not limited to: The instrument must consist of: sound-attenuating boxes needed to attenuate any potential disturbance from outside environment (sound, light and more); testing chamber grid floor where the animals stand; nose poke where the animals make responses to get the drug; light in the nose poke whole where the animals operant behaviors will be conditioned; syringe pump to control the drug delivery; house light in the chamber; interface module that operates the self-administration system; food self-administration training. As drug reward is differentially regulated compared to natural reward (e.g. food), we need to see whether some manipulations (e.g., pharmacological tools or gene therapies) are affecting drug reward or natural food reward. It is required the operating software can be used to control Self-Administration, Condition Place Preference, Shuttle box, Five and Nine Choice serial reaction tasks. These are the behavioral tasks that are related to examine the drug-related memory and drug abuse-induced behavioral changes (avoidance, attention deficits, etc.).