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Convergence and Segregation of Ventral Striatal Inputs and Outputs
Author(s) -
GROENEWEGEN HENK J.,
WRIGHT CHRISTOPHER I.,
BEIJER ARNO V.J.,
VOORN PIETER
Publication year - 1999
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.1999.tb09260.x
Subject(s) - anterograde tracing , neuroscience , nucleus accumbens , efferent , basal ganglia , striatum , ventral striatum , claustrum , ventral pallidum , retrograde tracing , thalamus , neurochemical , axoplasmic transport , afferent , infralimbic cortex , midbrain , putamen , anatomy , biology , nucleus , prefrontal cortex , globus pallidus , central nervous system , dopamine , cognition
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.