Regulatory Mechanisms of Neuron to Vessel Communication in the Brain

The highest level of integrative brain function requires the existence of homeostatic mechanisms aimed to the maintenance of the internal cerebral milieu. In fact, marked fluctuations in the extracellular fluid concentration of neurotransmitters, amino acids, hormones, nutrients, ions, can interfere with the neuronal processes, which are dependent on the chemical composition of the cerebral microenvironment. For example, significant changes in K+ concentration can adversely affect neuronal activity, and trigger a cascade of events which may ultimately be deleterious for the cell. The evolution in parallel of the high level of cerebral integrative processes and the efficiency of dynamic mechanisms for the regulation of brain milieu is supportive of the hypothesis that homeostasis and isolation are the principles that ensure a correct brain function.