Functional neuroanatomy of the prefrontal cortex: autonomic interactions

This chapter discusses recent research into the involvement of the prefrontal cortex (PFC) in autonomic control and describes the anatomical connections through which the PFC can exert these actions. Recent studies, either using in vivo neuronal stimulation, or fMRI scanning techniques, all point to a role of the orbital and medial prefrontal cortex, including the anterior cingulate area, in the modulation of the autonomic responses. The connections of the PFC areas with hypothalamic areas were considered the most important route, via which the prefrontal cortex could influence the autonomic and endocrine responses that accompany emotional processes. However, newly developed tracing methods have demonstrated that the mPFC also directly projects to the sympathetic and parasympathetic brain centers, and can, therefore, be expected to have a more widespread role as modulator in the regulation and coordination of autonomic responses than previously thought. Furthermore, the anatomical studies showed that within the mPFC there is a dichotomy in the projections from the rostral dorsomedial areas and the more caudal ventromedial areas. These differences in projection patterns could, on one hand, explain the opposing responses that have been reported to result from the stimulation of adjacent PFC areas.