Feline pial arteries larger than 100 mu in diameter constricted in response to cervical sympathetic nerve stimulation suggests or in response to topical application of norepinephrine. Smaller pial arteries were unresponsive to norepinephrine. This unresponsiveness persisted when norepinephrine was dissolved in CSF with high calcium ion concentration, or in CSF with both high calcium ion and zer...

In vivo imaging of mouse brain vasculature typically requires applying skull window opening techniques: open-skull cranial window or thinned-skull cranial window. We report non-invasive 3D in vivo cerebral blood flow imaging of C57/BL mouse by the use of ultra-high sensitive optical microangiography (UHS-OMAG) and Doppler optical microangiography (DOMAG) techniques to evaluate two cranial windo...

Over the past years the nitrous oxide absorption method proposed by Kety and Schmidt12 has achieved wide application for the estimation of the blood flow through the cerebral tissue as a whole. However, histological evidence indicates a great variability in the relative vascularity of the several portions of the brain. Thus, for the most part, the white matter is relatively poorly supplied with...

We evaluated the effect of a stable synthetic prostacyclin analogue, TRK-100, on the microcirculatory derangement occurring in feline pial vessels with endothelial damage after middle cerebral artery occlusion. Fifteen adult cats were divided into an untreated group (Group 1, n = 8) and a treated group (Group 2, n = 7). Thirty minutes after 10 minutes of ultraviolet irradiation, which selective...

The goal of our study was to examine the effects of infusion of serotonin and the thromboxane A2 analogue U46619 into one carotid artery to stimulate their release from platelets during aggregation. We measured blood flow to the brain and eye using microspheres and cerebral microvascular pressure in the pial arteries of normal and atherosclerotic cynomolgus monkeys. Unilateral intracarotid infu...

Pial arterioles supplying the hindlimb somatosensory cortex dilate in response to contralateral sciatic nerve stimulation. The mechanism of this pial vasodilation is not well understood. One possibility is that vasoactive metabolites released during brain activation may diffuse to subarachnoid cerebrospinal fluid (CSF) to dilate pial vessels. To test this hypothesis, we implanted closed cranial...

We review the organizational principles of the cortical vasculature and the underlying patterns of blood flow under normal conditions and in response to occlusion of single vessels. The cortex is sourced by a two-dimensional network of pial arterioles that feeds a three-dimensional network of subsurface microvessels in close proximity to neurons and glia. Blood flow within the surface and subsu...

This experimental model was designed to assess the mouse pial microcirculation during acute and chronic, physiological and pathophysiological hemodynamic, inflammatory and metabolic conditions, using in vivo fluorescence microscopy. A closed cranial window is placed over the left parieto-occipital cortex of the mice. Local microcirculation is recorded in real time through the window using epi a...

IT IS worthwhile noting at the outset that this controversy is not new, the topic having been debated with vigor for the past 100 years or so. What has changed is the way in which the question at issue has been posed. In earlier experiments, the question was whether or not vasomotor nerves existed; but once they had been demonstrated, the problem was to assign a functional role to them. By the ...

The purpose of this study was to examine hemodynamic mechanisms which protect cerebral vessels against chronic hypertension, and contribute to protective effects of sympathetic nerves in the cerebral circulation. We studied stroke-prone spontaneously hypertensive rats and normotensive Wistar-Kyoto rats. At 3-4 weeks of age, all rats underwent removal of one superior cervical sympathetic ganglio...