[Intercellular space and nonsynaptic interneuronal connections of the mammalian brain]

Electron-microscopic investigations of various parts of the CNS in laboratory mammals and man have demonstrated that a single cerebral intercellular space, presenting an immediate internal medium for the nervous tissue elements, has different structure at the border separating the media. Here is a complex of structures, included into composition of the hemato-encephalic and liquor-encephalic barrier. Data of the literature on chemical composition of the intercellular contents and on specific membranous receptors make it possible to suppose a communication role of the intercellular spaces, ensuring nonsynaptic intercellular connections and modulation of the synaptic transmission. At the level of membranes, that make walls of the intercellular clefts by means of certain phylogenetically ancient humoral mechanisms, interaction of systems of synaptic and nonsynaptic interneuronal connections is secured.