A General Circuitry Processing Reward/Aversion Information and Its Implications for Neuropsychiatric Illness

Neuroimaging experiments in humans have provided strong evidence for a generalized circuitry that processes reward/aversion information. Composed of an extended set of subcortical gray matter regions and the surrounding paralimbic cortical girdle, these neural systems form the core of an information backbone (iBM) for motivated behavior. Components of this iBM appear to be affected in several neuropsychiatric illnesses. Circuitry-based quantitative measures of these IBM components, as heritable and state indices, may provide better etiologic insights than the diagnostic categories based on statistical clusters of behaviors and symptoms used in current psychiatric diagnosis. Recent studies have alluded to parallels between the events at the molecular and brain circuitry levels during presentation of motivationally salient stimuli. This chapter will explore how integrative systems biology approaches can bridge the distributed neural circuits responsible for the processing of reward/aversion function and the networks of genes responsible for the development and maintenance of these neural circuits. These combined genetics and integrative neuroscience approaches have the potential to redefine our conceptualization of neuropsychiatric illnesses with the implementation of objective quantitative measures.