Assessing delay discounting in mice

Delay discounting (also intertemporal choice or impulsive choice) is the process by which delayed outcomes, such as delayed food delivery, are valued less than the same outcomes delivered immediately or with a shorter delay. This process is of interest because many psychopathologies, including substance dependence, pathological gambling, attention deficit hyperactivity disorder, and conduct disorder, are characterized by heightened levels of delay discounting. Some of these disorders are heritable, and data indicate that delay discounting also has a genetic component. To identify the genes underlying the delay discounting decision-making process and genetic correlates of heightened discounting, researchers have used mouse models. This unit describes a protocol for generating delay discounting behavior in mice and discusses analysis techniques for such behavior.