Considerations on the astroglial architecture and the columnar organization of the cerebral cortex.

Present knowledge on astroglial roles in brain organization and function indicates that these cells can regulate the extracellular ionic composition and modulate neuronal activity. In this regard, the "panglial synctium" formed by electrically and chemically coupled stellate astrocytes ("general mammalian" architecture) is believed to provide an intracellular pathway for the redistribution of ions and molecules within the cerebral cortex. Long astroglial interlaminar processes ("primate-specific" architecture) that run parallel to apical dendrites in the cerebral cortex of primates, may provide additional properties to the glial participation in cortical physiology and function. Since these processes are exclusively present within the primate order, functional models of cortical computations for these species should incorporate the astroglial interlaminar architecture in addition to the panglial synctium. This study analyzes possible implications of interlaminar astroglial processes, for the regulation of the extracellular ionic composition and segregation of functional columns in the cerebral cortex.