The term basal forebrain refers to a set of structures in the rostral ventromedial part of the cerebral hemisphere. It includes the substantia innominata, basal nucleus, olfactory tubercle, islands of Calleja and parts of the striatum and globus pallidus. It extends caudally into pars reticulata of the substantia nigra and rostrally includes the nucleus accumbens, nucleus of the diagonal band, nuclei of stria terminalis and septal nuclei ( Mai-2004 ).Considering the location of its substructures, the BFB would more accurately be referred to as 'basal cerebrum', but that term does not appear in the English literature ( Ngram ). Updated 26 Apr 2025.