Patterns of fiber degeneration in the dorsal lateral geniculate nucleus of the cat following lesions in the visual cortex

1967 ◽  
Vol 130 (3) ◽  
pp. 197-221 ◽  
Author(s):  
R. W. Guillery
Keyword(s):  
Visual Cortex ◽  
Lateral Geniculate Nucleus ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Lateral Geniculate ◽  
Dorsal Lateral Geniculate

Age dependent modification of cytochrome oxidase activity in the cat dorsal lateral geniculate nucleus following removal of primary visual cortex

1996 ◽  
Vol 13 (5) ◽  
pp. 805-816 ◽  
Author(s):  
Bertram R. Payne ◽  
Stephen G. Lomber
Keyword(s):  
Visual Cortex ◽  
Cytochrome Oxidase ◽  
Lateral Geniculate Nucleus ◽  
Oxidase Activity ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Cytochrome Oxidase Activity ◽  
Lateral Geniculate ◽  
Areas 17 And 18 ◽  
C Complex ◽  
Dorsal Lateral Geniculate

AbstractThe purpose of the present study was to assess changes in the levels of cytochrome oxidase (CO) activity in the dorsal lateral geniculate nucleus (dLGN) of the adult cat following removal of primary visual cortical areas 17 and 18 on the day of birth (P1), P28, or in adulthood (≫6 months). Cytochrome oxidase activity was measured in histological sections 9 or more months after the cortical ablation. Control measures obtained from intact cats show that CO activity is normally highest in the A-laminae of dLGN, and slightly lower in the C-complex. Following visual cortex ablations incurred at any age, CO activity levels are reduced in the A-laminae. This reduction is most profound following ablations incurred on P28 or in adulthood. In contrast, CO activity in the C-complex of dLGN is at nearly normal levels following ablations on P1 or P28, but not in adulthood. These findings contribute to our understanding of the role played by the dLGN in the transfer of visual signals along retino-geniculo-extrastriate pathways that expand following early removal of areas 17 and 18. Moreover, they have implications for our understanding of spared behavioral functions attributed to the extrastriate cortex in cats which incurred early damage of areas 17 and 18.

The β sector of the rabbit's dorsal lateral geniculate nucleus

1988 ◽  
Vol 233 (1270) ◽  
pp. 17-32 ◽  
Keyword(s):  
Visual Cortex ◽  
Lateral Geniculate Nucleus ◽  
Cortical Neurons ◽  
Main Part ◽  
Small Region ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Axon Terminals ◽  
Perigeniculate Nucleus ◽  
Lateral Geniculate ◽  
Dorsal Lateral Geniculate

The β sector of the rabbit’s dorsal lateral geniculate nucleus is a small region of nerve cells scattered among the fibres of the geniculocortical pathway. In its topographical relations it resembles the perigeniculate nucleus of carnivores, which contains neurons driven by geniculate and visual cortical neurons and which sends inhibitory fibres back into the geniculate relay. We have traced retinogeniculate, geniculocortical and corticogeniculate pathways in rabbits by using horseradish peroxidase or radioactively labelled proline and have found that the β sector resembles the perigeniculate nucleus in receiving no direct retinal afferents, sending no efferents to the visual cortex (V–I), and receiving afferents from the visual cortex. The corticogeniculate afferents are organized so that the visual field map in the β sector and the main part of the lateral geniculate relays are aligned, as are the maps in the cat’s perigeniculate nucleus and the main part of the geniculate relay of carnivores. Electron microscopical studies show similar types of axon terminals in the rabbit and the cat for the main part of the geniculate relay on the one hand and for the β sector and the perigeniculate nucleus on the other. Earlier observations that the proportion of putative inhibitory terminals (F-type terminals) is lower in the rabbit’s than the cat’s geniculate region are confirmed. A major difference between the β sector and the perigeniculate nucleus has been revealed by immunohistochemical staining for GABA. Whereas almost all of the cat’s perigeniculate cells appear to be GABA ergic, the proportion in the β sector is much lower, and not significantly different from that found in the main part of the rabbit’s geniculate relay. It is concluded that the β sector shares many of the organizational features of the perigeniculate nucleus. A common developmental origin seems probable, but the functional differences remain to be explored.

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