[Cytoarchitectonic and quantitative characteristics of cell groupings in layer IV of the cerebral cortex in the vibrissa representation area of the rat].

The multicellular neuronal groups named "barrels", which make the posterior-medial subfield of barrels and situate in IV layer of the somatosensory area of the rat cerebral cortex in the zone of the vibrissa representation have been studied. Average volumetric meanings and the number of neurons have been obtained in the barrels of various size and in the parts composing them (walls and cavities). As comparison of the results obtained demonstrated, there is a not proportional increase of the characteristics studied in the large and small barrels. An attempt is made to state the dependence of the quantitative characteristics of the barrels on the length of corresponding vibrissae and on the function they perform. It is possible to suggest that the size of the cortical projections of certain vibrissae depend not on the length of the vibrissae themselves, but rather on the volume of information they obtained. Analysing the peculiar features of morpho-functional organization of the posterio-medial subfield of the barrels, it is possible to suggest that complication of the vibrissa function is morphologically expressed as an increasing number of neurons predominantly in the walls of their corresponding barrels and in increasing volume of the cavities filled with the thalamo-cortical specific afferents.