The small cellular part of the red nucleus.

Nucleus ruber, pars parvocellularis

The small cell (parvocellular) part of the nucleus ruber receives signals from the dentatus nucleus of the cerebellum and gives rise to the central tegmentary pathway terminating in the olivainferior complex. The central tegment pathway is excitatory and is part of it from the cerebellum, to the olivainferior complex, outgoing the driving signaling circuit.

The nucleus also receives the influx of signals from (among other things) the premotor cortex.