Volume 877, Issue 1 p. 49-63

Convergence and Segregation of Ventral Striatal Inputs and Outputs

HENK J. GROENEWEGEN

Corresponding Author

HENK J. GROENEWEGEN

Graduate School Neurosciences Amsterdam, Research Institute Neurosciences Vrije Universiteit, Department of Anatomy, Vrije Universiteit, Amsterdam, The Netherlands

Address for correspondence: H.J. Groenewegen, M.D. Ph.D., Department of Anatomy and Embryology, Faculty of Medicine, Vrije Universiteit, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands. Voice: 31-20-444-8040; fax: 31-20-444-8054; [email protected]Search for more papers by this author
CHRISTOPHER I. WRIGHT

CHRISTOPHER I. WRIGHT

Graduate School Neurosciences Amsterdam, Research Institute Neurosciences Vrije Universiteit, Department of Anatomy, Vrije Universiteit, Amsterdam, The Netherlands

Department of Neurology, Harvard Medical School, Brigham and Women's Hospital, Boston MA, USA.

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ARNO V.J. BEIJER

ARNO V.J. BEIJER

Graduate School Neurosciences Amsterdam, Research Institute Neurosciences Vrije Universiteit, Department of Anatomy, Vrije Universiteit, Amsterdam, The Netherlands

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PIETER VOORN

PIETER VOORN

Graduate School Neurosciences Amsterdam, Research Institute Neurosciences Vrije Universiteit, Department of Anatomy, Vrije Universiteit, Amsterdam, The Netherlands

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First published: 06 February 2006
Citations: 490

Abstract

ABSTRACT: The ventral striatum, which prominently includes the nucleus accumbens (Acb), is a heterogeneous area. Within the Acb of rats, a peripherally located shell and a centrally situated core can be recognized that have different connectional, neurochemical, and functional identities. Although the Acb core resembles in many respects the dorsally adjacent caudate-putamen complex in its striatal character, the Acb shell has, in addition to striatal features, a more diverse array of neurochemical characteristics, and afferent and efferent connections. Inputs and outputs of the Acb, in particular of the shell, are inhomogeneously distributed, resulting in a mosaical arrangement of concentrations of afferent fibers and terminals and clusters of output neurons. To determine the precise relationships between the distributional patterns of various afferents (e.g., from the prefrontal cortex, the basal amygdaloid complex, the hippocampal formation, and the midline/intralaminar thalamic nuclei) and efferents to the ventral pallidum and mesencephalon, neuroanatomical anterograde and retrograde tracing experiments were carried out. The results of the double anterograde, double retrograde, and anterograde/retrograde tracing experiments indicate that various parts of the shell (dorsomedial, ventromedial, ventral, and lateral) and the core (medial and lateral) have different input-output characteristics. Furthermore, within these Acb regions, various populations of neurons can be identified, arranged in a cluster-like fashion, onto which specific sets of afferents converge and that project to particular output stations, distinct from the input-output relationships of neighboring, cluster-like neuronal populations. These results support the idea that the nucleus accumbens may consist of a collection of neuronal ensembles with different input-output relationships and, presumably, different functional characteristics.