Motor function of the cerebellorubrospinal system.

Two strinking features of the anatomic relations of the cerebellorubral pathway stand out. The first is that this pathway is comprised of numerous feedback connections, as is illustrated by the schematic diagram shown in Figure 1. Fibers descending from the red nucleus send prominent collaterals to brain stem nuclei (PCN). Many of these nuclei are a major source of mossy fiber input to the cerebellar cortex, and they provide collateral input to the cerebellar nuclei. In mammals, there is a relatively direct two-neuron recurrent loop between the nucleus interpositus and the NRTP