Analysis of the efferent projections of the lateral geniculate nucleus with special reference to the innervation of the subcommissural organ and related areas

1994 ◽  
Vol 277 (3) ◽  
pp. 437-445 ◽  
Author(s):  
Jens D. Mikkelsen
Keyword(s):  
Special Reference ◽  
Lateral Geniculate Nucleus ◽  
Subcommissural Organ ◽  
Lateral Geniculate ◽  
Efferent Projections

Organization of reciprocal connections between the perigeniculate nucleus and dorsal lateral geniculate nucleus in the cat: A transneuronal transport study

2002 ◽  
Vol 19 (4) ◽  
pp. 511-520 ◽  
Author(s):  
T. FITZGIBBON
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Ocular Dominance ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Thalamic Reticular Nucleus ◽  
Reticular Nucleus ◽  
Perigeniculate Nucleus ◽  
Lateral Geniculate ◽  
Efferent Projections ◽  
Contralateral Eye ◽  
Dorsal Lateral Geniculate

Cells of the cat's perigeniculate nucleus (PGN), part of the visual sector of the thalamic reticular nucleus (TRN), provide GABAergic inhibition to the A and A1 layers of the dorsal lateral geniculate nucleus (LGNd) and, therefore, may control information flow from the retina to the cortex. Previous electrophysiological experiments suggested that the PGN may be subdivided on the basis of ocular dominance thus reflecting the afferent and efferent projections with lamina A and A1 of the LGNd. The present study utilized the ability of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) to be transported transneuronally following intraocular injections in four cats to examine whether there is any anatomical evidence for eye specific layers within the PGN. Sections were processed with tetramethylbenzidine. Light WGA-HRP transneuronal labeling of LGNd collaterals and somata were seen in the PGN and very light labeling (but not somata) was seen in the TRN. Neither the cells of the PGN projecting to the LGNd nor the LGNd relay collaterals within the PGN were clearly organized into nonoverlapping laminae related to the eye specific layers of the LGNd. However, parts of the PGN immediately adjacent to the LGNd appear devoid of connections with lamina A1 thus creating a thin monocular segment for the contralateral eye.

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