The ventral striatum is a part of the brain. It's a part of the brain structure known as the striatum and is interconnected with the limbic system. It's believed that the ventral striatum has some involvement in motor movement as well as some emotional responses, particularly those related to pleasure and behavioral motivation.
The striatum, also known as the neostratium or the striate nucleus, is a subcortical structure, meaning that it's located deep inside the brain. It's situated in the forebrain, which is the area behind the frontal bone in the forehead region. "Striatum" is a collective term for the interconnection of several brain structures, which, together, are part of the deep brain structure known as the basal ganglia. The neostratium is a gray and white striped mass of matter located in front of the thalamus in both cerebral hemispheres. The cerebral hemispheres are the two halves of the brain, and they are divided by a line called the longitudinal cerebral fissure.
The dorsal striatum is located above the ventral striatum. The word "dorsal" means "above" or "on top of," and "ventral" means "below" or "underneath." The ventral striatum is located on the underside of the dorsal striatum. They are individual structures that are interconnected, and both are formed by the interconnection of other structures.
The structures called the caudate nucleus and the lentiform nucleus, or lenticular nucleus, together form the dorsal striatum. The caudate nucleus is a long curved mass of gray matter. The lentiform nucleus is made up of the structures called the globus pallidus and the putamen. Both structures of the lentiform nucleus together with the caudate nucleus form the corpus striatum, or the striate body, which is also the dorsal striatum.
The two structures that form the ventral striatum are the nucleus accumbens and the olfactory tubercle. Also called the accumbens nucleus, the nucleus accumbens is found at the head of the caudate nucleus and the front part of the putamen. Both halves of the brain contain one nucleus accumbens, which is divided into two structures: the nucleus accumbens core and the nucleus accumbens shell.
The second part of the ventral striatum, the olfactory tubercle, is a small ovular area found at the base of the cerebral hemispheres. The olfactory tubercle plays a part in olfaction, or the sense of smell. It contains granular cells called the islands of Calleja. In primates, the islands of Calleja are found mostly in the nucleus accumbens because the olfactory tubercle is much smaller than in other animals.