Regulation of nervous system function by circumventricular organs

Abstract

In this chapter, we highlight the specialized features of the sensory circumventricular organs (CVO) as central nervous system (CNS) structures located at the blood-brain interface. These structures appear to play critical roles in sensing and integrating information regarding autonomic status derived from circulating signals that do not readily cross the BBB. Intriguingly, while the majority of the original literature highlighting such roles attributed primarily fluid balance and cardiovascular functions to the subfornical organ (SFO) and metabolic function to the area postrema (AP), more recent work as highlighted in this chapter has clearly demonstrated, not only overlap in these physiological roles in SFO and AP, but also additional roles for these CVOs in reproductive and of primary importance to this chapter immune signaling from the circulation to the CNS. Within not only SFO and AP, but also the organum vasculosum of the lamina terminalis, the emerging literature supports the conclusion that single neurons in these CVOs sense, and presumably integrate, signals related to all of these separately classified autonomic functions. In recognizing the potential for such integration in the sensory CVOs, it becomes important to also understand that optimal health is associated with the ability of our physiological systems to regulate these functions in an integrated rather than separate manner.