The medullary cerebrovascular vasodilator area mediates cerebrovascular vasodilation and electroencephalogram synchronization elicited from cerebellar fastigial nucleus in Sprague–Dawley rats

We investigated whether the medullary cerebrovasodilator area (MCVA), a region of ventral medulla mediating elevations of regional cerebral blood flow (rCBF) and electroencephalogram (EEG) synchronization elicited in cerebral cortex from stimulation of reticulospinal neurons of rostral ventrolateral medulla (RVLM), also mediates comparable responses from the cerebellar fastigial nucleus (FN). In spinalized rats, electrical stimulation of MCVA, RVLM or FN elevated rCBF and synchronized the EEG. The FN-evoked responses were significantly attenuated or blocked by bilateral lesions of MCVA. The MCVA is a novel region of medullary reticular formation mediating actions of medullary and cerebellar centers on rCBF and EEG to link visceral centers of brainstem and cerebral cortex.