Morphology of physiologically identified retinogeniculate X- and Y-axons in the cat

1987 ◽  
Vol 58 (1) ◽  
pp. 1-32 ◽  
Author(s):  
M. Sur ◽  
M. Esguerra ◽  
P. E. Garraghty ◽  
M. F. Kritzer ◽  
S. M. Sherman
Keyword(s):  
Horseradish Peroxidase ◽  
Lateral Geniculate Nucleus ◽  
Morphological Analysis ◽  
Optic Tract ◽  
Pial Surface ◽  
Lateral Geniculate ◽  
Physiological Properties ◽  
Terminal Arbor ◽  
Subsequent Application ◽  
Adult Cats

1.We studied the morphology of individual, physiologically identified retinogeniculate axons in normal adult cats. The axons were recorded in the lateral geniculate nucleus or in the subjacent optic tract, characterized as X or Y by physiological criteria, penetrated, and injected with horseradish peroxidase. With subsequent application of appropriate histochemistry, the enzyme provides a complete label of the terminal arbors and parent trunks for morphological analysis. We have recovered for such analysis 26 X- and 25 Y-axons; of these, 14 X- and 12 Y-axons were studied in detail. 2. Within the optic tract, the parent trunk of every X-axon is located closer to the lateral geniculate nucleus and thus further from the pial surface than that of every Y-axon. This probably reflects the earlier development of X- than of Y-axons. Furthermore, the parent axon trunks of the X-axons are noticeably thinner than are those of the Y-axons. Every retinogeniculate X- and Y-axon in our sample branches within the optic tract. One of these branches heads dorsally to innervate the lateral geniculate nucleus and one heads medially and rostrally toward the midbrain, although none of these labeled axons were traced to a terminal arbor beyond the lateral geniculate nucleus. For Y-axons, all branches are of comparable diameter, but for X-axons, the branch heading toward the lateral geniculate nucleus is always noticeably thicker than is the branch directed toward the midbrain. 3. Every retinogeniculate X- and Y-axon produces the greatest portion of its terminal arbor in lamina A (if from the contralateral retina) or A1 (if from the ipsilateral retina). These arbors typically extend across most of the lamina along a projection line. Not a single terminal bouton from any axon was found in the inappropriate lamina A or A1 (i.e., in lamina A for ipsilaterally projecting axons or in lamina A1 for contralaterally projecting ones). Occasionally, an X-axon also innervates the medial interlaminar nucleus, and even more rarely does an X-axon innervate the C-laminae. In contrast, nearly all Y-axons from the contralateral retina branch to innervate part of the C-laminae (probably lamina C), and most from either retina also innervate the medial interlaminar nucleus. Although these details imply considerable variation in the overall pattern of retinogeniculate innervation for both X- and Y-axons, we found no physiological properties to correlate with this variation.(ABSTRACT TRUNCATED AT 400 WORDS)

The development of the retinogeniculate pathways in normal and albino ferrets

1984 ◽  
Vol 223 (1231) ◽  
pp. 141-164 ◽  
Keyword(s):  
Horseradish Peroxidase ◽  
Lateral Geniculate Nucleus ◽  
Optic Tract ◽  
Small Cell ◽  
Abnormal Distribution ◽  
Lateral Geniculate ◽  
Abnormal Pattern ◽  
Retinogeniculate Projection ◽  
Development Proceeds ◽  
Primary Action

The retinogeniculate pathways of normal and albino ferrets have been studied with horseradish peroxidase and tritiated proline used as axonal markers. The uncrossed retinogeniculate projection of adult albino ferrets is abnormally small and occupies only a fraction of the geniculate area normally occupied by uncrossed afferents. The crossed pathway is correspondingly expanded, occupying almost the entire nucleus. The geniculate laminae in the albino ferret are abnormal, showing abnormal fusions between layers receiving crossed input and abnormal discontinuities next to the small cell islands receiving uncrossed afferents. In early development, retinofugal fibres can be labelled within the optic tracts on the 28th intrauterine day and a few crossed fibres can be traced into the lateral geniculate nucleus. At this stage, the uncrossed component is extremely small in normal and albino animals and cannot be traced beyond the tract. By day 32 retinal fibres are invading the lateral geniculate nucleus bilaterally, the invasion by the crossed component being significantly more advanced than that by the uncrossed component. The uncrossed pathway of the albinos is already abnormal in terms of its size, in terms of the position it occupies in the optic tract, and in terms of its limited invasion of the lateral geniculate nucleus. The abnormally reduced size of the uncrossed component appears earlier than the abnormal segregation of the retinogeniculate terminals, suggesting that the primary action of the albino gene upon central visual pathways is prechiasmatic. At postnatal stages (41 days after conception and older) the normal, gradual withdrawal of the uncrossed fibres from the monocular segment, and the separation of crossed from uncrossed retinogeniculate terminal arbors is significantly delayed in the albinos. The uncrossed retinogeniculate terminals are abnormally sparse initially and become distributed in an abnormal, interrupted pattern as development proceeds. The abnormal pattern of geniculate lamination appears to be secondary to the abnormal distribution of retinogeniculate afferents.

NMDAR-1 staining in the lateral geniculate nucleus of normal and visually deprived cats

2000 ◽  
Vol 17 (2) ◽  
pp. 187-196 ◽  
Author(s):  
JOKUBAS ZIBURKUS ◽  
MARTHA E. BICKFORD ◽  
WILLIAM GUIDO
Keyword(s):  
Nmda Receptors ◽  
Lateral Geniculate Nucleus ◽  
Cell Labeling ◽  
Acid Decarboxylase ◽  
Thalamic Nuclei ◽  
Neurofilament Protein ◽  
Lateral Geniculate ◽  
Wide Range ◽  
Soma Size ◽  
Adult Cats

In normal adult cats, a monoclonal antibody directed toward the NR-1 subunit of the N-methyl-d-aspartate (NMDA) receptor (Pharmingen, clone 54.1) produced dense cellular and neuropil labeling throughout all layers of the lateral geniculate nucleus (LGN) and adjacent thalamic nuclei, including the thalamic reticular, perigeniculate, medial intralaminar, and ventral lateral geniculate nuclei. Cellular staining revealed well-defined somata, and in some cases proximal dendrites. NMDAR-1 cell labeling was also evident in the LGN of early postnatal kittens, suggesting that developing LGN cells possess this receptor subunit at or before eye opening. Within the A-layers of the adult LGN, staining encompassed a wide range of soma sizes. Soma size comparisons of NMDAR-1 stained cells with those stained with an antibody directed toward a nonphosphorylated neurofilament protein (SMI-32), which selectively stains Y-relay cells (Bickford et al., 1998), or an antibody to glutamic acid decarboxylase (GAD), which stains for GABAergic interneurons, suggested that NMDA receptors are utilized by relay cells and interneurons. NMDAR-1 staining was also observed in the LGN of cats with early monocular lid suture. Although labeling was apparent in both deprived and nondeprived A-layers of LGN, the distribution of soma sizes was significantly different. In the deprived A-layers of LGN, staining was limited to small- and medium-sized cells. Cells with relatively large soma were lacking. However, cell density measurements as well as soma size comparisons with cells stained for Nissl substance suggested these differences were due to deprivation-induced cell shrinkage and not to a loss of NMDAR-1 staining in Y-cells. Taken together, these results suggest that NMDA receptors are utilized by both relay cells and interneurons in LGN and that alterations in early visual experience do not necessarily affect the expression of NMDA receptors in the LGN.

Ultrastructural study of the avian ventral lateral geniculate nucleus

1991 ◽  
Vol 6 (2) ◽  
pp. 119-134 ◽  
Author(s):  
Gloria D. Guiloff
Keyword(s):  
Electron Microscopy ◽  
Horseradish Peroxidase ◽  
Lateral Geniculate Nucleus ◽  
Ultrastructural Study ◽  
Lateral Geniculate

AbstractThe ultrastructure of the pigeon and quail ventral lateral geniculate nucleus was analyzed with standard electron microscopy and horseradish peroxidase tracing of its retinal and tectal afferents. Six types of neurons were distinguished: two large, two medium-sized, and two small types.

Retinal Projections in the Northern Native Cat, Dasyurus-Hallucatus (Marsupialia, Dasyuridae)

1987 ◽  
Vol 35 (2) ◽  
pp. 115 ◽  
Author(s):  
AM Harman ◽  
DP Crewther ◽  
JE Nelson ◽  
SG Crewther
Keyword(s):  
Superior Colliculus ◽  
Lateral Geniculate Nucleus ◽  
Optic Tract ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Accessory Optic System ◽  
Anterograde Transport ◽  
Retinal Projections ◽  
Lateral Geniculate ◽  
Contralateral Eye ◽  
Dorsal Lateral Geniculate

The retinal projections of the northern native cat, Dasyurus hallucatus, were studied by the anterograde transport of tritiated proline and by autoradiography. Seven regions in the brain were found to receive direct retinal projections: (1) the suprachiasmatic nucleus; (2) the dorsal lateral geniculate nucleus; (3) the ventral lateral geniculate nucleus; (4) the lateral posterior nucleus; (5) the nuclei of the accessory optic tract; (6) the pretectal nuclei; (7) the superior colliculus. All nuclei studied received a bilateral retinal projection except the medial terminal nucleus of the accessory optic system, in which only a contralateral input was found. The contralateral eye had a greater input in all cases. As with the related species, Dasyurus viverrinus, there is extensive binocular overlap in the dorsal lateral geniculate nucleus (LGNd). In the LGNd contralateral to the injected eye, the autoradiographs show four contralateral terminal bands occupying most of the nucleus. The axonal terminations in the ipsilateral LGNd are more diffuse but show a faint lamination pattern of four bands. The ventral portion of the LGNd receives only contralateral retinal input, and therefore probably represents the monocular visual field. The other principal termination of the optic nerve, the superior colliculus, has a predominantly contralateral input to both sublayers of the stratum griseum superficiale. However, the ipsilateral fibres terminate only in patches in the more inferior sublayer.

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