The general topography of cortical inputs to the striatum and overall functional correlates has given rise to concept of parallel and segregated motivational, cognitive, and motor control basal ganglia (BG) loops. However, accumulating evidence demonstrates a potential role of integration across circuits for striatal mediation of cortical executive function. The overall hypothesis of the Center is that striatal dopaminergic hyperactivity leads to cortical dopamine dysfunction. The goal of P3 is to delineate the circuitry that underlies ventral striatal influence on the cognitive function in dorsolateral prefrontal cortex. The driving hypothesis of this project is that there are both parallel and integrative networks that together comprise a system that underlies striatal dopamine effects on cortical processing. Our laboratory focuses on the cortico-BG circuits that are critical for developing appropriate behavioral responses.
We have shown two key points of integration between limbic and cognitive systems: 1) through a series of striato-nigro-striatal connections in which a set of reciprocal and nonreciprocal connections results in information transfer from limbic to cognitive striatal regions. 2) through the prefrontal cortico-BG network that combines both topographical and non-topographical rules linking distinct components of the cortical circuits to specific striatal and thalamic regions. These nodal points of converging inputs provide subcircuits by which information processing can occur across functional domains. Importantly, there are similar convergent cortical projection patterns in the rodent.