Mechanisms of neurovascular coupling

Abstract

The brain is characterized by a well-developed vascular network and consumes a significant proportion of cardiac output relative to its mass. Normally, the metabolic needs of the brain significantly depend on the intensity of the functioning of its various departments, which requires constant regulation of the level of local blood flow. On the other hand, the state of systemic hemodynamics can have a significant impact on organ blood flow. Moreover, the importance of accurate and prompt regulation of cerebral blood flow is determined by the lack of energy reserves or substrates for its autonomous production in the nervous tissue and the huge role of the central nervous system in ensuring all physiological processes. In this regard, the organ cerebral blood flow has complex physiological mechanisms of regulation, which are implemented at various levels. At the same time, myogenic reactions are isolated, which occur when the degree of stretching of the smooth muscle cells of the vascular wall changes under the influence of pressure in the lumen of the vessel, as well as under the influence of local humoral effects, including those exerted by metabolites, on vascular tone at the level of the neurovascular unit. This review considers in detail the role of the neurovascular unit in the regulation of cerebral blood flow and the provision of the so-called neurovascular conjugation – a flexible dynamic correspondence between the level of local neuronal activity and the delivery of oxygen and nutrients. The mechanisms and essential importance of neurovascular coupling in the regulation of local cerebral blood flow, which ensures the development of functional hyperemia, as well as the performance several other functions, such as the delivery and removal of metabolites, temperature regulation, and the formation of cerebrospinal fluid, are demonstrated.