2023 Volume 60 Issue 4 Pages 172-180
Circumventricular organs (CVOs) are rich in blood vessels, but lack a blood-brain barrier, and are important regulators of life homeostasis. CVOs include sensory CVOs and secretory CVOs. The sensory CVOs include the subfornical organ, the organum vasculosum of the lamina terminalis, and the area postrema. Environmental stress signals such as angiotensin II and sodium ion concentrations sensed by these organs are neurotransmitted to the hypothalamic paraventricular nucleus. The secretory CVOs include the neurohypophysis, the pineal gland, the subcommissural organ, and the median eminence. They are responsible for the regulation of body fluid and osmolarity, sleep and sex hormones, immune and energy metabolism, and feeding behavior via hormone secretion functions. Although the choroid plexus is not strictly included in CVOs, it secretes cerebrospinal fluid under the control of the autonomic nervous system and is also important as a disordered organ of COVID-19. Kuroiwa et al. proposed the term "circumventricular organs dysregulation syndrome" or "hypothalamic syndrome" for conditions caused by dysregulation of CVOs and the hypothalamus.
