Subdivisions of the interpeduncular nucleus: a proposed nomenclature.

A compromise terminology for subdivisions is proposed which integrates the two previous standard and two recent and more detailed subnuclear schemes. The unpaired median subnuclei are called rostral, central and apical. The paired subnuclei are called rostral lateral, dorsal lateral, intermediate and lateral. A plea is made for attention to these consistent subdivisions, and for uniformity of terminology regardless of the parameters studied.