 Detailed examination of the region in the cat, however, suggested that the lateral part should be further divided into ten distinct subnuclei and the medial into five distinct subnuclei.Various species exhibit left-right asymmetric differentiation of habenular neurons.In many fishes and amphibians, the habenula on one side is significantly larger and better organized into distinct nuclei in the dorsal diencephalon than its smaller pair.