Adrenergic and cholinergic modulation of cerebrovascular nitrergic vasodilation

Large cerebral arteries at the base of the brain from several species are innervated by dense sympathetic adrenergic nerves, and parasympathetic cholinergic and nitrergic nerves. Norepinephrine (NE) and acetylcholine (ACh) released from the respective nerves are not the primary postsynaptic transmitters for vasoconstriction and dilation. Evidence has been presented to indicate that nitric oxide (NO) is the predominant transmitter for cerebral vasodilation. NE and ACh act as presynaptic transmitters in modulating NO release and therefore cerebral vascular tone. This transmitter mechanism in the large cerebral arteries appears to be different from that in the smaller vessels.