Evidence for in vivo cerebrovascular neurogenic vasodilatation in the rat.
To determine the function of cerebrovascular parasympathetic nerves, the calibre of rat pial arteries was continuously measured when the nerves (the postganglionic fibres originating from the sphenopalatine ganglion) were electrically stimulated in vivo. The pial arteries (72.3 +/- 2.8 microns) dilated immediately after electrical stimulation (5 V, 10 Hz, 0.5 ms, 1 min duration). Their diameter increased 4.7 +/- 0.1% (p less than 0.01), 6.3 +/- 1.7%, 5.1 +/- 0.3% (p less than 0.05), 6.3 +/- 1.4%, at 15, 30, 45 and 60 s after initiation of stimulation, respectively. No significant change was observed in systemic arterial blood pressure or the expiratory carbon dioxide content during stimulation. This is the first direct demonstration of in vivo cerebrovascular neurogenic vasodilatation in the rat.
Suzuki
N
N
Department of Neurology, Keio University, Tokyo, Japan.
Gotoh
F
F
Gotoh
J
J
Koto
A
A
D000818:Animals; D002536:Cerebral Arteries / Q000294:innervation; D002560:Cerebrovascular Circulation; D004558:Electric Stimulation; D005726:Ganglia, Parasympathetic / Q000502:physiology; D009412:Nerve Fibers / Q000502:physiology; D010275:Parasympathetic Nervous System / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012668:Trigeminal Ganglion / Q000502:physiology*; D014664:Vasodilation