Infusion of 400 microliters air into the left internal carotid artery of five anesthetized rabbits caused transient pial arteriole air embolism, an immediate 41.9 +/- 0.8% dilatation of the embolized vessels, suppression of the cortical somatosensory evoked response to 29.4 +/- 2.7% of baseline, and a progressive decline in ipsilateral cerebral blood flow (measured by hydrogen clearance) to 46 ...

Dural arteriovenous shunts and pial arteriovenous fistulas are uncommonly associated. Their etiology, pathogenesis, and natural history are still unclear and are likely different. We present three cases of high-flow dural arteriovenous shunts associated with pial arteriovenous fistulas and discuss their pathogenesis, anatomic association, and angioarchitecture. We propose that venous steal effe...

The diameters of pial arterioles of mice were monitored in vivo with an image-splitting technique and television microscopy. Concentrations of leukotriene C4 as low as 10(-7) M constricted the arterioles. The leukotriene C4-D4 receptor blocker ICI 198615 (10(-8) M) inhibited the response. Endothelial injury by helium-neon laser/Evans blue technique eliminated the constriction and unmasked a sli...

Introduction Moyamoya disease is a rare cerebrovascular occlusive disease of unknown etiology, characterized by stenosis or occlusion of both internal carotid arteries (ICAs) at the supraclinoid portion and an abnormal vascular network (moyamoya vessels)(1). 3-T MR angiography clearly shows moyamoya vessels at the base of the brain (2). Gadolinium-enhanced MRI depicts dilated pial vessels (ivy ...

Pial arterioles actively change diameter to regulate blood flow to the cortex. However, it is unclear whether arteriole reactivity and its homeostatic role of conserving red blood cell (RBC) flux remains intact after a transient period of ischemia. To examine this issue, we measured vasodynamics in pial arteriole networks that overlie the stroke penumbra during transient middle cerebral artery ...

The influence of sympathetic nervous activity on cerebral circulation and cerebrovascular CO2 reactivity was investigated through inhibition of dopamine beta-hydroxylase (DBH). A PO2 electrode, a PCO2 electrode and a plate-type thermocouple-flowmeter were placed on the pial surface of the cat brain. Cerebrocortical PO2, PCO2, cerebrocortical blood flow and arterial blood pressure were continuou...

background: the mechanisms underlying cerebral hypercapnic vasodilatation are not fully understood.   objective: to investigate the role of nitric oxide (no) and atp-sensitive potassium (k atp ) channels in basal blood flow regulation and hypercapnia-induced vasodilatation in rabbit cerebral blood vessels.   methods: the change in cerebral blood flow was measured by a laser doppler flowmeter in...

Complex barriers at the brain's surface, particularly in development, are poorly defined. In the adult, arachnoid blood-cerebrospinal fluid (CSF) barrier separates the fenestrated dural vessels from the CSF by means of a cell layer joined by tight junctions. Outer CSF-brain barrier provides diffusion restriction between brain and subarachnoid CSF through an initial radial glial end feet layer c...