Geniculocortical projection to layer I of area 17 in kittens: Orthograde and retrograde HRP studies

1984 ◽  
Vol 225 (3) ◽  
pp. 441-447 ◽  
Author(s):  
Nobuo Kato ◽  
Saburo Kawaguchi ◽  
Hirofumi Miyata
Keyword(s):  
Area 17 ◽  
Layer I ◽  
Geniculocortical Projection

Subcortical projections to layer I of the visual cortex, area 17, of the rat

1981 ◽  
Vol 41 (2) ◽  
Author(s):  
J.G. Parnavelas ◽  
A. Chatzissavidou ◽  
R.A. Burne
Keyword(s):  
Visual Cortex ◽  
Area 17 ◽  
Cortex Area ◽  
Layer I

Termination of thalamic intralaminar nuclei afferents in visual cortex of squirrel monkey

1990 ◽  
Vol 5 (2) ◽  
pp. 151-154 ◽  
Author(s):  
Lex C. Towns ◽  
Johannes Tigges ◽  
Margarete Tigges
Keyword(s):  
Visual Cortex ◽  
Squirrel Monkey ◽  
Occipital Cortex ◽  
Area 17 ◽  
Intralaminar Nuclei ◽  
Layer I

AbstractThe projection of the thalamic intralaminar nuclei (ILN) upon the visual cortex in the squirrel monkey was studied using anterograde, autoradiographic techniques. In area 17, the ILN afferents terminate in the inner and outer portions of lamina V, whereas in areas 18 and 19 the fibers terminate more diffusely along the laminae V–VI boundary. Widespread labeling of layer I is seen throughout the occipital cortex.

scholarly journals Pulvinar Modulates Synchrony across Visual Cortical Areas

Vision ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 22
Author(s):  
Nelson Cortes ◽  
Bruno O. F. de Souza ◽  
Christian Casanova
Keyword(s):  
Visual Cortex ◽  
Granger Causality ◽  
Gamma Oscillations ◽  
Oscillatory Activity ◽  
Area 17 ◽  
Feedback Processing ◽  
Area 21A ◽  
Layer I ◽  
Oscillatory Coupling ◽  
Visual Cortical

The cortical visual hierarchy communicates in different oscillatory ranges. While gamma waves influence the feedforward processing, alpha oscillations travel in the feedback direction. Little is known how this oscillatory cortical communication depends on an alternative route that involves the pulvinar nucleus of the thalamus. We investigated whether the oscillatory coupling between the primary visual cortex (area 17) and area 21a depends on the transthalamic pathway involving the pulvinar in cats. To that end, visual evoked responses were recorded in areas 17 and 21a before, during and after inactivation of the pulvinar. Local field potentials were analyzed with Wavelet and Granger causality tools to determine the oscillatory coupling between layers. The results indicate that cortical oscillatory activity was enhanced during pulvinar inactivation, in particular for area 21a. In area 17, alpha band responses were represented in layers II/III. In area 21a, gamma oscillations, except for layer I, were significantly increased, especially in layer IV. Granger causality showed that the pulvinar modulated the oscillatory information between areas 17 and 21a in gamma and alpha bands for the feedforward and feedback processing, respectively. Together, these findings indicate that the pulvinar is involved in the mechanisms underlying oscillatory communication along the visual cortex.

scholarly journals Calcium-binding proteins immunoreactivity in the human subcortical and cortical visual structures

1996 ◽  
Vol 13 (6) ◽  
pp. 997-1009 ◽  
Author(s):  
G. Leuba ◽  
K. Saini
Keyword(s):  
Visual Cortex ◽  
Superior Colliculus ◽  
Lateral Geniculate Nucleus ◽  
Calcium Binding ◽  
Binding Proteins ◽  
Calcium Binding Proteins ◽  
Area 17 ◽  
Optic Radiation ◽  
Lateral Geniculate ◽  
Layer I

AbstractThe distribution of neurons and fibers immunoreactive (ir) to the three calcium-binding proteins parvalbumin (PV), calbindin D-28k (CB), and calretinin (CR) was studied in the human lateral geniculate nucleus (LGN), lateral inferior pulvinar, and optic radiation, and related to that in the visual cortex. In the LGN, PV, CR, and CB immunoreactivity was present in all laminae, slightly stronger in the magnocellular than in the parvocellular laminae for CB and CR. PV-ir puncta, representing transversally cut axons, and CR-ir fibers were revealed within the laminae and interlaminar zones, and just beyond the outer border of lamina 6 in the geniculate capsule. In the optic radiation both PV- and CR-immunoreactive neurons, puncta, and fibers were present. CB immunoreactivity was revealed in neurons of all laminae of the lateral geniculate nucleus, including S lamina and interlaminar zones. There were hardly any CB-ir puncta or fibers in the laminae, interlaminar zones, geniculate capsule, or optic radiation. In the lateral inferior pulvinar, immunoreactive neurons for the three calcium-binding proteins were present in smaller number than in the LGN, as well as PV-ir puncta and CR-ir fibers within the nucleus and in the pulvinar capsule. In the white matter underlying area 17, fibers intermingled with a few scattered neurons were stained for both PV and CR, but very rarely for CB. These fibers stopped at the limit between areas 17 and 18. Area 17 showed a dense plexus of PV-ir puncta and neurons in the thalamo-receptive layer IV and CR-ir puncta and neurons both in the superficial layers I-II, IIIC, and in layer VA. Cajal-Retzius CR-ir neurons were present in layer I. CB-ir puncta were almost confined to layer I-III and CB-ir neurons to layer II. Finally the superior colliculus exhibited mostly populations of PV and CR pyramidal-like immunoreactive neurons, mainly in the intermediate tier. These data suggest that in the visual thalamus most calcium-binding protein immunoreactive neurons project to the visual cortex, while in the superior colliculus a smaller immunoreactive population represent projection neurons.

An experimental study of the termination of the lateral geniculo–cortical pathway in the cat and monkey

1971 ◽  
Vol 179 (1054) ◽  
pp. 41-63 ◽  
Keyword(s):  
Visual Cortex ◽  
Stellate Cell ◽  
Stellate Cells ◽  
Area 17 ◽  
Electron Microscopic ◽  
Area 18 ◽  
Terminal Degeneration ◽  
Layer V ◽  
Layer I ◽  
Almost All

The thalamic projection to the visual cortex has been studied in the cat and monkey by experimental light and electron microscopic techniques. After large lesions of the lateral geniculate nucleus degeneration is confined to the ipsilateral hemisphere. In the cat it is found in areas 17, 18 and 19 and in the lateral suprasylvian area, terminal degeneration occurring predominantly in layer IV, with less in layers I, III and V ; fibre degeneration crossing layers VI and V towards layer IV is coarser in area 18 than elsewhere. Some fine horizontal degenerating fibres are seen in layer I. In the monkey terminal degeneration is restricted to area 17; again degenerating fibres ascend to layer IV where there is dense fragmentation, but in contrast to the cat there is also a second, less dense, but distinct, band in layer Illb. A little fine, horizontal fibre degeneration is present in layer I and there is slight terminal degeneration in this site and in layer V. Electron microscopy shows that degenerating terminals are recognizable in the visual cortex at several stages according to survival period, but that most stages can exist simultaneously in any one site, and that all are associated with asymmetrical membrane thickenings. Mapping of electron microscopic sections confirms the laminar pattern seen with the light microscope. In area 17 of the cat and monkey and in area 19 of the cat over 80% of degenerating terminals end on dendritic spines, the rest making synaptic contact mainly with dendritic shafts, and very few with the soma of stellate cells, but in area 18 some 10 % are related to stellate cell bodies. In layer IV of all areas degenerating terminals tend to occur in clusters which are separated by approximately 100 μ m. Where degenerating thalamic afferents end on cell somata or varicose dendrites almost all are identifiable as derived from stellate cells. Although it is difficult to identify positively the parent dendrites bearing the spines which receive the majority of the thalamo-cortical afferents, it is suggested that some, at least, of them may also originate from stellate cells.

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