Structuro-functional considerations of the cerebellar neuron network

The neuronal network of the cerebellar cortex is discussed with strong emphasis upon its structure, but taking into consideration the recently revealed functional properties of its various neuronal elements. From the viewpoint of the experimenter this neuron network has the unique advantage of being arranged in the form of a highly regular rectangular lattice and being built up of relatively few well-known structural elements. After consideration of certain structural features of the granular layer (the receiving area of one of the two main lines of input) which suggest some important preprocessing of the arriving information, the mode of transmission of this excitation to the main part of the cortex is discussed. A functional model of the operation of the main neuron network is then proposed, based on the known geometry and functional properties of the elements involved. Some additional speculations are made about the possible functional significance of the most unusual structural feature of the cerebellar cortex: the complete separation in space (compartmentalization) of the Purkinje cell dendritic trees.