A study on the microvasculature of the cerebellar cortex. The fundamental architecture and its senile change in the cerebellar hemisphere.

The arterial structure of the cerebellar cortex was studied by vascular stain and in diaphanized specimens after intra-arterial barium injections. A scanning electron microscope study on the corrosion cast of the arteries was also performed. Arteries distributed in the cerebellar hemisphere are classified into cortical, subcortical, and medullary arteries. The patterns of arterial distribution are similar to those in the cerebral cortex. The cortical arteries are subclassified into superficial, middle, and deep cortical branches. The superficial branches are very fine, forming capillary networks in the molecular layer. The middle cortical branches terminate in the Purkinje cell layer, by dividing into several branches extending parallel to the plane of this layer. These branches connect with capillaries in both the molecular and the granular layers. The deep cortical branches give off some collaterals along the Purkinje cell layer and terminate in the granular layer, by breaking up into capillary networks. The Purkinje cell layer is marked by arterial branches ramified from the middle and deep cortical branches and no particular dense capillary networks are formed in the Purkinje cell layer. The brains of older patients show intertwining of the middle and deep cortical branches, some forming "rope-like" appearance. These patterns are similar to those seen in the cerebral cortex, but they were found, in older people, in the cerebrum.