Neostriatum

The neostriatum is a compound structure comprised of the putamen and caudate nucleus. In birds, it also includes the high vocal center ; it has evolved into a structure nowadays called nidopallium.

Afferents are sent to the neostriatum from the thalamus and cerebrum.

Warning
Some sources consider the term "neostriatum" to be a misleading name leading to dubious and often obsolete concepts. In mammals, the term striatum alone should be used in order to avoid confusion. This element of the telencephalon comprises the whole continuous mass, constituted by the same neuronal species, made up of the putamen, the caudate nucleus and the fundus.

The term striatum is a simplification proposed by C. and O. Vogt (1941) to replace the disparate "corpus striatum" of classics.

The obsolete anatomical term neostriatum was previously used for designating one part of complex subdivisions in reptiles and birds.Etymologically, neostriatum is a Greco-Latin bastard (not the first) "new" (neo in Ancient Greek) and striatum (from Latin). The adjective describes the striate aspect of the putamen principally striated by the radial fascicles of the striatopallidinigral bundle.

Another warning
There are two categories of "striate" parts of the brain:
 * 1-the (corpus) striatum, striated radially and subcortical
 * 2-the "striate" cortex (visual), striated horizontally as any other cortex, i.e. parallel to the surface.

The two worlds do not meet, as the primary visual cortex does not contribute to the basal ganglia system input in which the striatum is the main input station.

Phylogenesis
In opposition to the paleostriatum and archistriatum, the neostriatum used to refer to the part of the mammalian basal ganglia that was supposed to be present only in higher vertebrates. Indeed, birds were supposed to have evolved large hyperstriatum instead of neocortex. However, recent comparative anatomy works based on molecular biology and neuronal tracing have led to major revisions of the anatomical description of that part of the vertebrate telencephalon.

In birds, the neostriatum has been renamed nidopallium