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