XXXX in the @entity35 nucleus accumbens: ultrastructural localization in aspiny neurons receiving synaptic input from GABAergic terminals.

@entity10969 @entity1246 @entity3162 @entity367 @entity35
The ultrastructure, afferent input, and sites of termination of neurons containing @entity10969 -like immunoreactivity (NPY- @entity3162 ) were examined in the adult @entity35 nucleus accumbens by using the peroxidase-antiperoxidase (PAP) method. The NPY- @entity3162 was seen in sparsely distributed, spindle-shaped perikarya having cross-sectional diameters of 15-20 microns. These perikarya exhibited highly invaginated nuclear membranes and thin rims of cytoplasm containing Golgi lamellae, dense-core vesicles, and other organelles. A few large, principally aspiny, dendrites also showed NPY- @entity3162 . The dendrites received synaptic input from unlabeled terminals forming both symmetric and asymmetric junctions. Immunolabeling for NPY was evident in other processes that were not clearly differentiated as dendrites or axons. These were seen primarily near glial processes and the basal laminae of blood vessels. A few myelinated and many unmyelinated axons and axon terminals also were labeled for NPY. These terminals contained numerous, small (40-60 nm), clear and one or more large (80-100 nm) dense core vesicles. Forty-seven percent (27 out of 57) of the terminals containing NPY- @entity3162 formed symmetric junctions with unlabeled dendrites or dendritic spines. The remainder lacked recognizable densities within single planes of section. The neurons exhibiting NPY- @entity3162 in the nucleus accumbens were characterized further with respect to their afferent input from terminals labeled for the @entity1246 -synthesizing enzyme, @entity367 decarboxylase (GAD). Immunogold labeling of a rabbit antiserum against NPY and PAP labeling for a sheep antiserum to GAD were sequentially applied to the same sections. The GAD-labeled terminals formed symmetric junctions primarily with the more numerous unlabeled dendrites. However, a few synaptic junctions also were detected between the GAD-labeled terminals and dendrites showing immunogold labeling for NPY. We conclude (1) that in the @entity35 nucleus accumbens, NPY- @entity3162 is found principally in neurons of the aspiny type and (2) that the output from these presumably intrinsic neurons to other neighboring neurons or blood vessels is at least partially modulated by @entity1246 .
