aqueduct- Aq    
basilar artery- bas
deep grey layer of superior coll- DpG
intermediate gray layer sup col- InG
intermediate white layer sup col- InWh
lamina dissecans entorhinal- Dsc
oculomotor nu- 3
periacueductal grey- Pag
red nu. magnocellular- RMC
zonal layer superior colliculus- Zo