in the Human Brain: New Lessons from Perturbation and Imaging

Dopamine plays an important role in several brain functions and is involved in the pathogenesis of several psychiatric and neurological disorders. Neuroimaging techniques such as positron emission tomography allow us to quantify dopaminergic activity in the living human brain. Combining these with brain stimulation techniques offers us the unique opportunity to tackle questions regarding region-specific neurochemical activity. Such studies may aid clinicians and scientists to disentangle neural circuitries within the human brain and thereby help them to understand the underlying mechanisms of a given function in relation to brain diseases. Furthermore, it may also aid the development of alternative treatment approaches for various neurological and psychiatric conditions. Keywords brain imaging, dopamine, positron emission tomography, prefrontal cortex, transcranial magnetic stimulation Dopamine (DA) is involved in many cerebral functions, for example, learning, reward, motor control, emotion, and executive functions. Given its pervasiveness, the dopami-nergic system has been extensively targeted for the treat-ment of various psychiatric and neurological diseases