PRIMATE CINGULOSTRIATAL PROJECTION - LIMBIC STRIATAL VERSUS SENSORIMOTOR STRIATAL INPUT

The organization of the projections from the cingulate cortex to the s triatum in the monkey was studied using the retrograde tracers Lucifer Yellow conjugated to dextran amines and horseradish peroxidase conjug ated to wheat germ agglutinin. These tracers were injected into the di fferent regions of the ventral (Limbic) striatum and the dorsal (senso rimotor) striatum. The shell region of the nucleus accumbens was defin ed using calbindin-D-28K immunohistochemistry. Following injections in to the ventral striatum, there are numerous retrogradely labeled neuro ns in the various regions of the primate cingulate cotter, most of whi ch are derived from layer V. The cytoarchitectural subdivisions of cin gulate cortex include the anterior cingulate cortex, areas 25, 24a-c, and 24a'-c', and the posterior cingulate cortex, areas 23a-c, 29, 30, and 31. There is a topographical organization of the projections from these different cingulate areas to the ventral and dorsal striatum. Th e medial ventral striatum receives input from the rostral part of the anterior cingulate cortex (areas 25 and 24a,b). The shell region of th e nucleus accumbens receives fibers from areas 25, 24a,b, and 24a',b'. Projections to the central ventral striatum including the core of the nucleus accumbens are derived primarily from areas 25, 24a, 24b, and the medial part of area 24c. However, few labeled cells are detected i n areas 24c and 24c'. The lateral ventral striatum receives input prim arily from areas 24b, 24b' and 23b and medial portion of area 24c. The medial ventral striatum and the shell of the nucleus accumbens have a similar distribution of labeled cells, such that these regions derive their input almost entirely from the rostral anterior cingulate corte x. In contrast to the ventral striatum, the dorsal sensorimotor striat um receives projections from areas 24c, 24c' 23c and 31. These arise p rimarily from the lateral portion of lower bank and the fundus of the cingulate sulcus. Our results demonstrate that areas 24c, 24c' and 23c , the lateral portion of the lower bank and the fundus of the cingulat e sulcus project to the dorsal sensorimotor striatum. The medial porti on of the lower bank of the cingulate cortex projects to the ventral s triatum including the core of the nucleus accumbens. Different project ions to striatum from discrete subdivisions of cingulate cortex indica te that these areas are heterogeneous and have different functions suc h that the fundus of the cingulate sulcus is related to skeletomotor f unction, whereas the medial portion of the lower bank of the cingulate sulcus is associated with the limbic-related and association cortical function. The lateral portion of the lower bank may be a transition a rea and related to both motor and limbic functions. (C) 1994 Wiley-Lis s, Inc.