Pyramidal cells, the principal neurons of the dorsal cochlear nucleus in the rat, have a system of hypolemmal cisterns as prominent as that of cerebellar Purkinje cells. In their perikarya nearly all the subsurface cisterns are closely apposed to mitochondria as in Purkinje cells. This feature emphasizes a similarity between the two types of neuron which both have dendrites residing in the molecular layer. In addition, cochlear pyramidal neurons contain a distinct cytoplasmic cysternal core which includes cisternae with narrow lumina. These occasionally form simple and multiple assemblies with mitochondria.