On the spatial arrangement of iso-orientation bands in the cat's visual cortical areas 17 and 18: a 14C-Deoxyglucose study

1984 ◽  
Vol 56 (2) ◽  
Author(s):  
K. Albus ◽  
B. Sieber
Keyword(s):  
Spatial Arrangement ◽  
Cortical Areas ◽  
Areas 17 And 18 ◽  
Visual Cortical

An examination of linking hypotheses drawn from the perceptual consequences of experimentally induced changes in neural circuitry

2013 ◽  
Vol 30 (5-6) ◽  
pp. 271-276 ◽  
Author(s):  
DONALD E. MITCHELL ◽  
STEPHEN G. LOMBER
Keyword(s):  
Striate Cortex ◽  
Extended Period ◽  
Monocular Deprivation ◽  
Specific Cell ◽  
Cortical Areas ◽  
Good Spatial Resolution ◽  
Areas 17 And 18 ◽  
Visual Cortical ◽  
Areas Of Interest ◽  
Induced Changes

AbstractBecause targeted early experiential manipulations alter both perception and the response properties of particular cells in the striate cortex, they have been used as evidence for linking hypotheses between the two. However, such hypotheses assume that the effects of the early biased visual input are restricted to just the specific cell population and/or visual areas of interest and that the neural populations that contribute to the visual perception itself do not change. To examine this assumption, we measured the consequences for vision of an extended period of early monocular deprivation (MD) on a kitten (from 19 to 219 days of age) that began well before, and extended beyond, bilateral ablation of visual cortical areas 17 and 18 at 132 days of age. In agreement with previous work, the lesion reduced visual acuity by only a factor of two indicating that the neural sites, other than cortical areas 17 and 18, that support vision in their absence have good spatial resolution. However, these sites appear to be affected profoundly by MD as the effects on vision were just as severe as those observed following MD imposed on normal animals. The pervasive effects of selected early visual deprivation across many cortical areas reported here and elsewhere, together with the potential for perception to be mediated at a different neural site following deprivation than after typical rearing, points to a need for caution in the use of data from early experiential manipulations for formulation of linking hypotheses.

Topographic organization, number, and laminar distribution of callosal cells connecting visual cortical areas 17 and 18 of normally pigmented and Siamese cats

1992 ◽  
Vol 9 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Nancy E. J. Berman ◽  
Simon Grant
Keyword(s):  
Pyramidal Neurons ◽  
Area 17 ◽  
Vertical Meridian ◽  
Cortical Areas ◽  
Area Centralis ◽  
Areas 17 And 18 ◽  
Contralateral Eye ◽  
Visual Cortical ◽  
Callosal Pathway ◽  
Cell Zone

AbstractThe callosal connections between visual cortical areas 17 and 18 in adult normally pigmented and “Boston” Siamese cats were studied using degeneration methods, and by transport of WGA-HRP combined with electrophysiological mapping. In normal cats, over 90% of callosal neurons were located in the supragranular layers. The supragranular callosal cell zone spanned the area 17/18 border and extended, on average, some 2–3 mm into both areas to occupy a territory which was roughly co-extensive with the distribution of callosal terminations in these areas. The region of the visual field adjoining the vertical meridian that was represented by neurons in the supragranular callosal cell zone was shown to increase systematically with decreasing visual elevation. Thus, close to the area centralis, receptive-field centers recorded from within this zone extended only up to 5 deg into the contralateral hemifield but at elevations of -10 deg and -40 deg they extended as far as 8 deg and 14 deg, respectively, into this hemifield. This suggests an element of visual non-correspondence in the callosal pathway between these cortical areas, which may be an essential substrate for “coarse” stereopsis at the visual midline.In the Siamese cats, the callosal cell and termination zones in areas 17 and 18 were expanded in width compared to the normal animals, but the major components were less robust. The area 17/18 border was often devoid of callosal axons and, in particular, the number of supragranular layer neurons participating in the pathway were drastically reduced, to only about 25% of those found in the normally pigmented adults. The callosal zones contained representations of the contralateral and ipsilateral hemifields that were roughly mirror-symmetric about the vertical meridian, and both hemifield representations increased with decreasing visual elevation. The extent and severity of the anomalies observed were similar across individual cats, regardless of whether a strabismus was also present. The callosal pathway between these visual cortical areas in the Siamese cat has been considered “silent,” since nearly all neurons within its territory are activated only by the contralateral eye. The paucity of supragranular pyramidal neurons involved in the pathway may explain this silence.

Visual cortex damage-induced growth of retinal axons into the lateral posterior nucleus of the cat

1993 ◽  
Vol 10 (4) ◽  
pp. 747-752 ◽  
Author(s):  
Bertram R. Payne ◽  
Heather A. Foley ◽  
Stephen G. Lomber
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Cortical Areas ◽  
Retinal Axons ◽  
Lateral Posterior ◽  
Lateral Posterior Nucleus ◽  
Visual Field Maps ◽  
Areas 17 And 18 ◽  
Adult Cats ◽  
Visual Cortical

AbstractAblation of visual cortical areas 17 and 18 in neonatal and young adult cats induces novel retinal projections to terminate bilaterally in the lateral posterior nucleus (LP) at a position ventromedial from the medial interlaminar nucleus. Comparison with the visual-field maps of LP indicate that the terminations are focussed on the representation of the visual-field center.

Subcortical structures projecting to visual cortical areas in squirrel monkey

1982 ◽  
Vol 209 (1) ◽  
pp. 29-40 ◽  
Author(s):  
Johannes Tigges ◽  
M. Tigges ◽  
N. A. Cross ◽  
R. L. McBride ◽  
W. D. Letbetter ◽  
...  
Keyword(s):  
Squirrel Monkey ◽  
Subcortical Structures ◽  
Cortical Areas ◽  
Visual Cortical

scholarly journals Functional Specialization of Seven Mouse Visual Cortical Areas

Neuron ◽  
2011 ◽  
Vol 72 (6) ◽  
pp. 1040-1054 ◽  
Author(s):  
James H. Marshel ◽  
Marina E. Garrett ◽  
Ian Nauhaus ◽  
Edward M. Callaway
Keyword(s):  
Functional Specialization ◽  
Cortical Areas ◽  
Visual Cortical

Hedonic-Specific Activity in Piriform Cortex During Odor Imagery Mimics That During Odor Perception

2007 ◽  
Vol 98 (6) ◽  
pp. 3254-3262 ◽  
Author(s):  
Moustafa Bensafi ◽  
Noam Sobel ◽  
Rehan M. Khan
Keyword(s):  
Specific Activity ◽  
Piriform Cortex ◽  
Brain Regions ◽  
Specific Pattern ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Odor Perception ◽  
Cortical Areas ◽  
Visual Cortical ◽  
Left Insula

Although it is known that visual imagery is accompanied by activity in visual cortical areas, including primary visual cortex, whether olfactory imagery exists remains controversial. Here we asked whether cue-dependent olfactory imagery was similarly accompanied by activity in olfactory cortex, and in particular whether hedonic-specific patterns of activity evident in olfactory perception would also be present during olfactory imagery. We used functional magnetic resonance imaging to measure activity in subjects who alternated between smelling and imagining pleasant and unpleasant odors. Activity induced by imagining odors mimicked that induced by perceiving real odorants, not only in the particular brain regions activated, but also in its hedonic-specific pattern. For both real and imagined odors, unpleasant stimuli induced greater activity than pleasant stimuli in the left frontal portion of piriform cortex and left insula. These findings combine with findings from other modalities to suggest activation of primary sensory cortical structures during mental imagery of sensory events.

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