How are the caudate nucleus and putamen connected to each other?

The caudate nucleus and putamen are anatomically continuous with each other in the rostral and ventral regions of the brain. Together, these two structures are collectively referred to as the neostriatum, or simply the striatum.12

While they maintain distinct spatial configurations—with the putamen located deep within the cortex of the insular lobe and the caudate nucleus forming a C-shaped structure that parallels the lateral ventricle—they share similar cellular compositions, cytochemical features, and functional roles as the primary receptive component of the corpus striatum. Both nuclei receive diverse inputs from the cerebral cortex, the substantia nigra, and the thalamus, which terminate on the dendritic spines of their medium-sized spiny neurons.1