endoplasmic reticulum membrane stack cellular_component 2012-12-11T14:58:16Z GO:1990007 NIF_Subcellular:sao2114874506 pr A configuration of endoplasmic reticulum (ER) found in Purkinje cells in the cerebellum and in axons in the lateral vestibular nucleus, consisting of parallel and interconnecting tubules whose outer surfaces are covered by particles or ringlike structures.