Motivation in monkeys: dynamic interplay between catecholaminergic neurons and the prefrontal cortex
Motivation is central in our everyday life and it is altered in several neurological and psychiatric disorders, such as apathies or depressions. Neuromodulation is essential for numerous aspects of behavior, but the specific contribution of each neuromodulator to motivation remains unclear. We address this issue by combining electrophysiological and pharmacological approaches in monkeys. Our recent data emphasize a complementary role for dopamine (DA) and noradrenaline (NA) in motivation. Besides the classical role of DA in incentive processes, which facilitate behavior as a function of the expected reward, NA plays a critical role in effort production and facilitates behavior in the face of upcoming challenges. The fine regulation of behavior as a function of internal and external information relies on dynamic interactions betweens neuromodulatory systems and anterior structures such as the ventromedial prefrontal cortex. Understanding these dynamic interactions provides critical insight into the neurobiological processes underlying motivation.