title: Layer-specific dilation of penetrating arteries induced by stimulation of the nucleus basalis of Meynert in the mouse frontal cortex.
abstract: To clarify mechanisms through which activation of the nucleus basalis of Meynert (NBM) increases cerebral cortical blood flow, we examined whether cortical parenchymal arteries dilate during NBM stimulation in anesthetized mice. We used two-photon microscopy to measure the diameter of single penetrating arteries at different depths (~800 μm, layers I to V) of the frontal cortex, and examined changes in the diameter during focal electrical stimulation of the NBM (0.5 ms at 30 to 50 μA and 50 Hz) and hypercapnia (3% CO2 inhalation). Stimulation of the NBM caused diameter of penetrating arteries to increase by 9% to 13% of the prestimulus diameter throughout the different layers of the cortex, except at the cortical surface and upper part of layer V, where the diameter of penetrating arteries increased only slightly during NBM stimulation. Hypercapnia caused obvious dilation of the penetrating arteries in all cortical layers, including the surface arteries. The diameters began to increase within 1 second after the onset of NBM stimulation in the upper cortical layers, and later in lower layers. Our results indicate that activation of the NBM dilates cortical penetrating arteries in a layer-specific manner in magnitude and latency, presumably related to the density of cholinergic nerve terminals from the NBM.
authors.affiliation: Department of Autonomic Neuroscience, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo, Japan. hhotta@tmig.or.jp
authors.forename: Harumi
authors.initials: H
authors.lastname: Hotta
authors.forename: Kazuto
authors.initials: K
authors.lastname: Masamoto
authors.forename: Sae
authors.initials: S
authors.lastname: Uchida
authors.forename: Yuta
authors.initials: Y
authors.lastname: Sekiguchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takuwa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawaguchi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Shigemoto
authors.forename: Ryo
authors.initials: R
authors.lastname: Sudo
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tanishita
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ito
authors.forename: Iwao
authors.initials: I
authors.lastname: Kanno
mesh_terms: D000818:Animals; D020532:Basal Nucleus of Meynert / Q000033:anatomy & histology / Q000098:blood supply; D002536:Cerebral Arteries / Q000033:anatomy & histology / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D008297:Male; D051379:Mice; D014664:Vasodilation / Q000502:physiology*