Author/Editor		Perko, Denis; Zaletel, Marjan
Title		Pomen astrocitov, obžilnih živčnih vlaken in možganskega žilnega endotelija pri regulaciji možganskega krvnega pretoka
Translated title		Role of astrocytes, perivascular nerves and cerebrovascular endothelium in the regulation of cerebral blood flow
Type		članek
Source		Med Razgl
Vol. and No.		Letnik 47, št. 3
Publication year		2008
Volume		str. 283-91
Language		slo
Abstract		For normal function brain requires proper supply of oxygen and glucose in a timely and local manner. This is achieved through intercellular communications, a process known as nerovascular coupling. At least that is what was believed till today. Recent studies showed us that this process besides activated perivascular neurons also involves astrocycites. Together they alter local vascular tone and so adjust perfusion to the spatial and temporal changes in brain activity. Cerebral blood vessels at the surface and within the brain are surrounded by nerve fibres that originate, respectively, from peripheral nerve ganglia and intrinsic brain neurons. Although of different origin and targeting distinct vascular beds, perivascular nerves similarly reglate cerebrovascular tone and therein brain perfusion. Astrocytes, cells with extensive contacts with both synapses and cerebral blood vessels, also participate in the increases in flow evoked by synaptic activity. Their structural organization indicates that they are uniquely positioned to shape the spatial distribution of the vascular responses that are evoked by neural activity. Astrocytic calcium is an important determinant of microvascular function and may regulate flow independently of synaptic activity. Ultimately, cerebrovascular endothelium exerts a profound influence on cerebral vessels and cerebral blood flow. The endothelium contributes to the resting tone of cerebral arteries and arterioles by tonically releasing nitric oxide. It may participate in neurovascular coupling by conducting local dilations to upstream arteries. So nowadays we speak about neuro-astrocyte-vascular tripartite unit.
Descriptors		CEREBROVASCULAR CIRCULATION ENDOTHELIUM, VASCULAR ASTROCYTES CEREBRAL ARTERIES NITRIC OXIDE EPOPROSTENOL