Functional organization of the cat's visual cortex after prenatal interruption of binocular interactions.

Shook, Brenda L.; Maffei, Lamberto; Chalupa, Leo M.

doi:10.1073/pnas.82.11.3901

Cited by 16 publications

(4 citation statements)

References 24 publications

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“…Furthermore, monocular enucleation leaves cortical cell responses to other stimulus parameters relatively intact, although it is unknown how it affects the two-dimensional maps of these parameters (Fregnac et al, 1981;Shook et al, 1985;Bisti and Trimarchi, 1993;Bisti et al, 1995). Here, we show that early monocular enucleation leads to a loss of the ocular dominance map and causes changes in the remaining maps that are consistent with a dimension-reduction model of map organization.…”

Section: Introductionsupporting

confidence: 69%

Alteration of Visual Input Results in a Coordinated Reorganization of Multiple Visual Cortex Maps

Farley¹,

Yu²,

Jin³

et al. 2007

J. Neurosci.

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In the adult visual cortex, multiple feature maps exist and have characteristic spatial relationships with one another. The relationships can be reproduced by "dimension-reduction" computational models, suggesting that the principles of continuity and coverage may underlie cortical map organization. However, the mechanisms responsible for establishing these relationships are unknown. We explored whether removing one feature map during development causes a coordinated reorganization of the remaining maps or whether the remaining maps are unaffected. We removed the ocular dominance map by monocular enucleation in newborn ferrets, so that single eye stimulation drove the cortex in a more spatially uniform manner in adult monocular animals compared with normal animals. Maps of orientation, spatial frequency, and retinotopy formed in monocular ferrets, but their structures and spatial relationships differed from those in normal ferrets. The wavelength of the orientation map increased, so that the average orientation gradient across the cortex decreased. The decrease in the orientation gradient in monocular animals was most prominent in the high gradient regions of the spatial frequency map, indicating a coordinated reorganization between these two maps. In monocular animals, the orthogonal relationship between the orientation and spatial frequency maps was preserved, and the orthogonal relationship between the orientation and retinotopic maps became more pronounced. These results were consistent with detailed predictions of a dimension-reduction model of cortical organization. Thus, the number of feature maps in a cortical area influences the relationships between them, and inputs to the cortex have a significant role in generating these relationships.

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Section: Introductionsupporting

confidence: 69%

Alteration of Visual Input Results in a Coordinated Reorganization of Multiple Visual Cortex Maps

Farley¹,

Yu²,

Jin³

et al. 2007

J. Neurosci.

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“…Physiological studies of IC and auditory cortical neurons in contralaterally cochlear ablated animals have shown an increase in sensitivity and discharge level to stimulation of the ipsilateral (intact) ear (Kitzes, 1984;Kitzes and Semple, 1985;Reale et al, 1987). Unilateral eye enucleation during visual development has also been associated with an enhancement of sensitivity and spatial resolution in the remaining eye (Shook et al, 1985;Heywood et al, 1988). It may thus be a general rule that unilateral sensory deprivation early in life results in an increased level of sensitivity and discriminative capacity on the undeprived side.…”

Section: Brain-stem Projectionsmentioning

confidence: 99%

Auditory brain stem of the ferret: some effects of rearing with a unilateral ear plug on the cochlea, cochlear nucleus, and projections to the inferior colliculus

et al. 1989

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To examine the influence of acoustic experience on the development of the mammalian auditory brain stem, darkly pigmented ferrets were reared with a plug inserted in the right outer ear. The plugs were first inserted on postnatal day 23-34 and produced a variable, frequency-dependent attenuation of up to 60 dB. Between 3-15 months after the ear plug was begun, animals were prepared for physiological recording and injection of wheat germ agglutinin-HRP (WGA-HRP) in the left inferior colliculus (IC). The plug was removed and the condition of the right ear was assessed by pure-tone stimulation and recordings from neurons in the left IC. Neural audiograms for each animal showed a residual deficit in most cases. Following 24-60 hr survival, the animals were perfused and the right ear was examined. Brain-stem sections were reacted with tetramethylbenzidine. Outer and/or middle ear pathology was present in over half of the animals. However, the cochleas appeared to be normal and the spiral ganglion cells were normal by several quantitative criteria: number, area, and nucleolar eccentricity. The volume of each division of the cochlear nuclei (CN) and the areas of individual neurons in the anteroventral CN were the same on the right and left sides. The number of CN neurons retrogradely labeled from the left IC injection of WGA-HRP was found to be significantly increased in the left CN, relative to normal animals, when expressed as a ratio of the number labeled in the right CN. We conclude that the residual hearing loss in the previously plugged ears was predominantly or exclusively conductive. Neonatal, unilateral conductive hearing loss in the ferret does not lead to degeneration of the CN on the side of the loss, but it does lead to at least one rearrangement of auditory brain-stem connectivity. We suggest that the extent to which the brain stem is modified by early auditory deprivation is dependent on the type, degree, and symmetry of the hearing loss.

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“…Moreover, Heywood, Silveira and Cowey (1988), using averaged visually-evoked potentials, showed that the remaining eye of adult rats who had the other eye enucleated shortly after birth had substantially higher contrast sensitivity than that of normal rats tested monocularly. This has not been examined in other mammals but the receptive fields in striate cortex in cats deprived of one eye prenatally are smaller than those of normal cats (Shook, Maffei & Chalupa, 1985;Shook & Chalupa, 1986) even though the functional properties of cells in the dLGN that project to the striate cortex are not similarly altered (White, Chalupa, Maffei, Kirby & Lia, 1989).…”

Section: Introductionmentioning

confidence: 97%

Contrast sensitivity in one-eyed subjects

1996

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The effects of early monocular form deprivation on the developing mammalian visual system, and the anatomical and physiological consequences of early monocular enucleation, suggest that the remaining eye of human subjects who had the other eye removed early during development might be capable of supernormal performance. To test this inference, the achromatic contrast sensitivity of the remaining eye of subjects who had the other eye removed at different ages after birth was compared with that of normal subjects tested under monocular and binocular conditions. The results show that all subjects who had an eye removed during early development had a higher contrast sensitivity than the better eye of control subjects. Furthermore, the earlier in development that the eye was removed, the lower the spatial frequency at which contrast sensitivity is enhanced compared with measurements made in the better eye of control subjects, and the larger the range of spatial frequencies over which contrast sensitivity is supernormal.

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Functional organization of the cat's visual cortex after prenatal interruption of binocular interactions.

Cited by 16 publications

References 24 publications

Alteration of Visual Input Results in a Coordinated Reorganization of Multiple Visual Cortex Maps

Alteration of Visual Input Results in a Coordinated Reorganization of Multiple Visual Cortex Maps

Auditory brain stem of the ferret: some effects of rearing with a unilateral ear plug on the cochlea, cochlear nucleus, and projections to the inferior colliculus

Contrast sensitivity in one-eyed subjects

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