A Behavioural Technique for the Rapid Assessment of the Visual Capabilities of Kittens

Mitchell, Donald E.; Giffin, Fred; Timney, Brian

doi:10.1068/p060181

Cited by 98 publications

(40 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Pettigrew et al, 1988). In particular, in the domestic cat, which has been the subject of repeated, detailed studies of basic visual mechanisms, close agreement was found between the retinal resolution estimates from ganglion cell density (Hughes, 1985) and behavioral (Jacobson et al, 1976;Mitchell et al, 1977) and evoked-potential (Harris, 1978) results for visual acuity. Among marine mammals, good correspondence has also been found in the bottlenose dolphin between the retinal resolution estimated from ganglion cell densities (Mass and Supin, 1995) and behavioral measures of visual acuity (Herman et al, 1975).…”

Section: Ganglion Cell Density and Retinal Resolutionmentioning

confidence: 59%

Ganglion Cell Distribution and Retinal Resolution in the Florida Manatee, Trichechus Manatus Latirostris

Mass

Ketten

Odell

et al. 2011

The Anatomical Record

View full text Add to dashboard Cite

The topographic organization of retinal ganglion cells was examined in the Florida manatee (Trichechus manatus latirostris) to assess ganglion cell size and distribution and to estimate retinal resolution. The ganglion cell layer of the manatee's retina was comprised primarily of large neurons with broad intercellular spaces. Cell sizes varied from 10 to 60 lm in diameter (mean 24.3 lm). The retinal wholemounts from adult animals measured 446-501 mm 2 in area with total ganglion cell counts of 62,000-81,800 (mean 70,200). The cell density changed across the retina, with the maximum in the area below the optic disc and decreasing toward the retinal edges and in the immediate vicinity of the optic disc. The maximum cell density ranged from 235 to 337 cells per millimeter square in the adult retinae. Two wholemounts obtained from juvenile animals were 271 and 282 mm 2 in area with total cell numbers of 70,900 and 68,700, respectively (mean 69,800), that is, nearly equivalent to those of adults, but juvenile retinae consequently had maximum cell densities that were higher than those of adults: 478 and 491 cells per millimeter square. Calculations indicate a retinal resolution of $19 0 (1.6 cycles per degree) in both adult and juvenile retinae. Anat Rec, 295:177-186, 2012. V V C 2011 Wiley Periodicals, Inc.Key words: manatee; Trichechus manatus; eye; retina; ganglion cells; cell topography; cell size; retinal resolution; visual acuityThe Sirenia order includes the manatee, dugong, and the extinct Steller cow. Sirenians are adapted to salt and fresh water habitats and, unlike other marine mammals, are exclusively herbivorous. Consequently, they have a range of unique anatomical, physiological, and behavioral adaptations. Further, all species of the order are endangered. The West Indian manatee is a slow grazer that inhabits the coastal areas and rivers of the Caribbean basin (Bertram and Bertram, 1962;Hartman, 1979; Nowak, 1991). The Florida manatee, Trichechus manatus latirostris, is a subspecies of the West Indian manatee, T. manatus. Knowing more about their sensory abilities, including their visual abilities, is of interest not only for basic evolutionary research but also for planning strategies for conserving this highly endangered species.

show abstract

Section: Ganglion Cell Density and Retinal Resolutionmentioning

confidence: 59%

Ganglion Cell Distribution and Retinal Resolution in the Florida Manatee, Trichechus Manatus Latirostris

Mass

Ketten

Odell

et al. 2011

The Anatomical Record

View full text Add to dashboard Cite

show abstract

“…Visual acuity was measured in kittens using a two-alternative forced-choice discrimination task (30,44) (Fig. 2A).…”

Section: Temporary Retinal Inactivation Restores Visual Acuity In Ambmentioning

confidence: 99%

Rapid recovery from the effects of early monocular deprivation is enabled by temporary inactivation of the retinas

Fong

Mitchell

Duffy

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

A half-century of research on the consequences of monocular deprivation (MD) in animals has revealed a great deal about the pathophysiology of amblyopia. MD initiates synaptic changes in the visual cortex that reduce acuity and binocular vision by causing neurons to lose responsiveness to the deprived eye. However, much less is known about how deprivation-induced synaptic modifications can be reversed to restore normal visual function. One theoretically motivated hypothesis is that a period of inactivity can reduce the threshold for synaptic potentiation such that subsequent visual experience promotes synaptic strengthening and increased responsiveness in the visual cortex. Here we have reduced this idea to practice in two species. In young mice, we show that the otherwise stable loss of cortical responsiveness caused by MD is reversed when binocular visual experience follows temporary anesthetic inactivation of the retinas. In 3-mo-old kittens, we show that a severe impairment of visual acuity is also fully reversed by binocular experience following treatment and, further, that prolonged retinal inactivation alone can erase anatomical consequences of MD. We conclude that temporary retinal inactivation represents a highly efficacious means to promote recovery of function. A mblyopia is a widespread form of human visual disability that arises from imbalanced visual experience in the two eyes during infancy or early childhood. The core pathophysiological process underlying amblyopia is ocular dominance plasticity in the primary visual cortex (V1). Ocular dominance plasticity, evolutionarily conserved in mammals with binocular vision, has become a classic paradigm for studying how brain development is influenced by experience and deprivation. A brief period of monocular deprivation (MD) during early postnatal life causes functional depression of synapses in V1 that serve the deprived eye (1-7). Consequently, early-life MD severely and persistently degrades visual acuity through the deprived eye, which typically fails to recover spontaneously when binocular vision is restored (8-10). A critical step in developing targeted interventions for treating amblyopia is to identify strategies for reversing deprivation-driven synaptic modifications in V1.The traditional approach to promote recovery following MD has been to occlude the strong eye to force vision through the weak amblyopic eye. This "reverse occlusion" approach has been validated in animals (11, 12) and represents the cornerstone of current treatment (patching therapy) of human amblyopia (13-16). However, this treatment has well-known limitations that include poor compliance, potential loss of vision through the newly patched eye, failure to recover binocular vision, and a declining treatment efficacy with age (15, 17-21). Nevertheless, the success of reverse occlusion strategies demonstrates that severely weakened synaptic inputs in the brain can be rejuvenated under appropriate circumstances.An insight into how reverse occlusion might promote recovery came fr...

show abstract

“…The mask was removed to permit normal concordant binocular visual exposure (BE ). The initial studies examined the consequences of these various rearing conditions on the vision of the two eyes in terms of the visual acuity for square-wave gratings by use of a jumping stand (Mitchell et al 1977). Kittens were trained daily on the jumping stand from approximately five weeks of age for approximately 30 min per day during the period of BE.…”

Section: Animal Studies On Prevention Of Amblyopia and Restitution Ofmentioning

confidence: 99%

Neural mechanisms of recovery following early visual deprivation

Mitchell

Sengpiel

2008

Phil. Trans. R. Soc. B

Self Cite

View full text Add to dashboard Cite

Natural patterned early visual input is essential for the normal development of the central visual pathways and the visual capacities they sustain. Without visual input, the functional development of the visual system stalls not far from the state at birth, and if input is distorted or biased the visual system develops in an abnormal fashion resulting in specific visual deficits. Monocular deprivation, an extreme form of biased exposure, results in large anatomical and physiological changes in terms of territory innervated by the two eyes in primary visual cortex (V1) and to a loss of vision in the deprived eye reminiscent of that in human deprivation amblyopia. We review work that points to a special role for binocular visual input in the development of V1 and vision. Our unique approach has been to provide animals with mixed visual input each day, which consists of episodes of normal and biased (monocular) exposures. Short periods of concordant binocular input, if continuous, can offset much longer episodes of monocular deprivation to allow normal development of V1 and prevent amblyopia. Studies of animal models of patching therapy for amblyopia reveal that the benefits are both heightened and prolonged by daily episodes of binocular exposure.

show abstract

A Behavioural Technique for the Rapid Assessment of the Visual Capabilities of Kittens

Cited by 98 publications

References 19 publications

Ganglion Cell Distribution and Retinal Resolution in the Florida Manatee, Trichechus Manatus Latirostris

Ganglion Cell Distribution and Retinal Resolution in the Florida Manatee, Trichechus Manatus Latirostris

Rapid recovery from the effects of early monocular deprivation is enabled by temporary inactivation of the retinas

Neural mechanisms of recovery following early visual deprivation

Contact Info

Product

Resources

About