The Sympathoexcitatory Pathway from the CVL to the RVL for Controlling Brain Vessels

We reported a regional differentiation of blood flow responses during the activation of the nucleus tractus solitarius (NTS) and caudal ventrolateral medullary depressor area (CVL). The neurons in the NTS and CVL have a vasoconstrictor effect on brain circulation and a vasodilator effect on systemic circulation. On the other hand, the neurons in the rostral ventrolateral medullary pressor area (RVL) have a vasoconstrictor effect on both brain and systemic circulation. We therefore hypothesized that there is a sympathoexcitatory pathway from the CVL to the RVL for controlling cerebral vessels and a sympathoinhibitory pathway from the CVL to the RVL for controlling systemic vessels, and that these different roles of the pathways from the CVL to the RVL for the different organs can explain the regional difference in sympathetic nerve activities. Here, we propose a sympathoexcitatory pathway from the CVL to the RVL for controlling brain vessels.