The distribution of crossed and uncrossed optic fibers in the different layers of the lateral geniculate nucleus in the tree shrew (Tupaia glis)

1982 ◽  
Vol 164 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Ferenc Hajdu ◽  
Rolf Hassler ◽  
Aleksander Wagner
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Tree Shrew ◽  
Lateral Geniculate ◽  
Tupaia Glis ◽  
Optic Fibers

Laminar organization of tree shrew dorsal lateral geniculate nucleus

1983 ◽  
Vol 50 (6) ◽  
pp. 1330-1342 ◽  
Author(s):  
J. L. Conway ◽  
P. H. Schiller
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Tree Shrew ◽  
Visual Stimuli ◽  
Optic Tract ◽  
Cell Types ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Lateral Geniculate ◽  
Tupaia Glis ◽  
Dorsal Lateral Geniculate ◽  
Laminar Specificity

This study investigated the organization of the dorsal lateral geniculate nucleus (LGN) of the tree shrew (Tupaia glis) using both microelectrode recording and anatomical techniques. The tree shrew LGN contains approximately 100,000 cells, of which 20% are in layers 2 and 6. These two layers receive input from the ipsilateral eye. The topography of the tree shrew LGN was delineated by taking systematic penetrations through the structure. Examination of the organization of the LGN laminae showed the following: in layer 1 (the lamina next to the optic tract) a mixture of on-center, off-center and on-off center cells was found; the majority of these cells responded transiently to visual stimuli and they had slightly longer conduction latencies than did cells in the other laminae. On-center and off-center cells in laminae 2-6 were sharply segregated: layers 2, 3, and 4 contained off-center cells and layers 5 and 6 contained on-center cells. Most of the cells in laminae 2-6 responded in a sustained manner to visual stimuli. These results suggest that one function of the LGN lamina is to group cells into various classes. Such grouping has now been shown to occur partially or completely for 1) eye of origin, 2) cell types characterized as on-center and off-center, and 3) cell types characterized as producing transient and sustained responses. The nature and degree of laminar specificity, however, varies considerably from species to species.

scholarly journals Transformation of Receptive Field Properties from Lateral Geniculate Nucleus to Superficial V1 in the Tree Shrew

2013 ◽  
Vol 33 (28) ◽  
pp. 11494-11505 ◽  
Author(s):  
S. D. Van Hooser ◽  
A. Roy ◽  
H. J. Rhodes ◽  
J. H. Culp ◽  
D. Fitzpatrick
Keyword(s):  
Receptive Field ◽  
Lateral Geniculate Nucleus ◽  
Tree Shrew ◽  
Lateral Geniculate ◽  
Receptive Field Properties

Effects of eliminating retinal Y cell input on center-surround interactions in the dorsal lateral geniculate nucleus of the cat

1996 ◽  
Vol 13 (6) ◽  
pp. 1089-1097 ◽  
Author(s):  
Chun Wang ◽  
B. Dreher ◽  
W. Burke
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Ganglion Cells ◽  
Spot Size ◽  
Excitatory Input ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Optimal Size ◽  
Lateral Geniculate ◽  
Optic Fibers ◽  
Dorsal Lateral Geniculate ◽  
Suppression Index

AbstractThe aim of this project was to investigate the interaction between Y retinal ganglion cells and the cells of the dorsal lateral geniculate nucleus (LGNd) of the cat, with particular reference to center-surround antagonism and intrageniculate inhibition. Responses of cells in the LGNd were studied by stimulating the retina with spots of light of constant contrast but varying size. The peak discharges of nonlagged X (XN) cells were strongly suppressed with increase in spot size but the responses of lagged X (XL) cells and nonlagged Y (YN) cells were inhibited much less strongly. The effect of the Y system on these responses was examined by producing a selective block of conduction in Y fibers in one optic nerve by means of a pressure cuff (Y-blocking). These effects were assessed by measuring the peak discharge rates and by calculation of a “peak suppression index.” Y-blocking had no significant effect on the peak suppression index of XL, cells in either lamina or on YN cells in the normal (not Y-blocked) lamina but had significant effects on the responses of XN cells, causing a decrease in peak suppression index, both for cells in laminae receiving their principal excitatory input from the Y-blocked eye (both lamina A and lamina A1 ) as well as those in lamina A (but not lamina A1 ) receiving their excitatory input from the normal eye. These effects were obtained with relatively large spots of light. Thus Y optic fibers have both intralaminar (monocular) and interlaminar (binocular) inhibitory effects on XN cells. In addition to these suppressive effects, the experiments also show that ipsilaterally projecting Y fibers have facilitatory effects on XN cells in lamina A when small spots of light, about optimal size for the XN cell, are used. These results suggest that the Y system plays a powerful role in shaping the responses of XN cells, possibly enhancing visual acuity.

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