part of part of white matter of hindbrain pyramidal tract http://atlas.brain-map.org/atlas?atlas=138322605#structure=12773 http://atlas.brain-map.org/atlas?atlas=3#structure=12773 pyramidal tract ( human dev ) http://atlas.brain-map.org/atlas?atlas=265297126#structure=12773 py py http://atlas.brain-map.org/atlas?atlas=138322603#structure=12773