Classes of neurons in relation to the laminar organization of the lateral geniculate nucleus in the tree shrew,Tupaia belangeri

1987 ◽  
Vol 259 (1) ◽  
pp. 31-49 ◽  
Author(s):  
K. Saini ◽  
R. Kretz ◽  
G. Rager
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Tree Shrew ◽  
Laminar Organization ◽  
Tupaia Belangeri ◽  
Lateral Geniculate

Laminar organization and ultrastructure of GABA-immunoreactive neurons and processes in the dorsal lateral geniculate nucleus of the tree shrew (Tupaia belangeri)

1988 ◽  
Vol 1 (2) ◽  
pp. 189-204 ◽  
Author(s):  
Robert N. Holdefer ◽  
Thomas T. Norton ◽  
Ranney Mize R.
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Functional Organization ◽  
Tree Shrew ◽  
Visual Signals ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Gamma Aminobutyric Acid ◽  
Cross Sectional ◽  
Axon Terminals ◽  
Tupaia Belangeri ◽  
Lateral Geniculate

AbstractThe distribution and ultrastructure of neurons and neuropil labeled by an antiserum to gamma-aminobutyric acid (GABA) were examined in the lateral geniculate nucleus (LGN) of the tree shrew (Tupaia belangeri). The LGN of this species segregates center type and cell class into three distinct pairs of laminae: a medial pair (laminae 1 and 2) containing ON-center cells, a more lateral pair (4, 5) containing OFF-center cells, and 2 laminae (3, 6) containing W-like cells. The relationship between this laminar segregation and the distribution of GABA immunoreactivity was investigated in the present study. GABA-immunoreactive neurons and neuropil were present in all six of the laminae. However, both the density of labeled cells (adjusted for neuronal density across laminae) and the density of labeled neuropil showed a medial-to-lateral gradient. The adjusted density of labeled cells was higher laterally than medially, and the density of labeled neuropil was significantly greater in the more lateral OFF-center laminae and W-like laminae than in the medial two ON-center laminae. Thus, inhibitory, GABAergic influences may modulate to different degrees the visual signals in the ON, OFF, and W pathways. Labeled cells had a mean cross-sectional area (107 μm2) approximately one-half that of unlabeled cells (216 μm2). They constitute 16–34% of the neurons in the LGN. At the electron microscope level, three different kinds of labeled profile were observed. Vesicle containing profiles like the F2 profiles of cat were postsynaptic to retinal terminals and presynaptic to conventional dendrites. Fl axon terminals with dense clusters of vesicles were also labeled as were some myelinated axons. Another labeled profile, which we suggest should be called an F3 process, was a large dendrite of irregular caliber with punctate groups of vesicles near the synapse. Our results suggest that GABAergic circuitry is an important part of the functional organization in the LGN of the tree shrew.

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
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