Motivated behavior can be characterized by a high degree of activity, vigor, and persistence. Brain dopamine (DA), particularly in the nucleus accumbens, has been implicated in activational aspects of motivation and effort-related processes. Accumbens DA depletions reduce the tendency of rats to work for food, and alter effort-related decision making, but leave aspects of food motivation such as appetite intact. Recent evidence indicates that the purine neuromodulator adenosine, largely through actions on adenosine A2A receptors, also participates in regulating effort-related processes. Intra-accumbens injections of adenosine A2A agonists produce effects that are similar to those produced by accumbens DA depletion or antagonism. Furthermore, systemic or intra-accumbens injections of adenosine A2A receptor antagonists can reverse the effects of DA D2 antagonists on effort-related choice behavior. In contrast, adenosine A1 receptor antagonists fail to reverse these motivational effects of DA D2 antagonism. These studies have implications for understanding the potential role of adenosine in the development and treatment of energy-related motivational symptoms such as anergia and fatigue in depression and other disorders.
|Title of host publication
|Subtitle of host publication
|A Key Link between Metabolism and Brain Activity
|Springer New York
|Number of pages
|Published - Nov 1 2013
All Science Journal Classification (ASJC) codes