Biomaterial Database

Optokinetic nystagmus in cats with congenital strabismus. 1996

K P Hoffmann, and C Distler, and C Markner

Allgemeine Zoologie und Neurobiologie, Ruhr-Universität Bochum, Germany.

1. Eye movements were recorded in seven innately esotropic cats during monocular and binocular horizontal optokinetic stimulation, using the search coil technique in five cats and electrooculography in two cats. 2. During closed loop measurements in these strabismic cats, slow phases of optokinetic nystagmus (OKN) were characterized by an overall reduced gain when compared with normal controls. In addition, response gain to monocular nasotemporal stimulation was even more reduced than that to temporonasal stimulation, resulting in an increased asymmetry of closed loop gain. 3. During open loop measurements, eye velocity in strabismic cats was very low at all velocities tested. 4. Differential analysis of the symmetry of OKN revealed that all our strabismic cats had a "good" or more symmetric and a "poor" or more asymmetric eye. In addition, when analyzed separately at individual velocities, the symmetry index of the good eye was fairly constant over the velocity range tested. By contrast, the symmetry index of the poor eye dropped dramatically at higher stimulus velocities. 5. To analyze the relationship of OKN symmetry and cortical physiology, we calculated the ratio between the percentage of neurons driven by one eye in the ipsilateral and the contralateral cortical hemisphere. We found a weak correlation between OKN symmetry and this cortical symmetry index (P < 0.05, analysis of variance). 6. In conclusion, slow eye movements in cats with congenital esotropia are characterized by extremely low gain, especially at higher stimulus velocities. In addition, OKN symmetry during monocular stimulation is decreased. Our data suggest that OKN symmetry is weakly correlated with the proportion of binocular neurons in the visual cortex ipsilateral to the stimulated eye. However, OKN characteristics seem to reflect to a higher degree the response properties of neurons in the pretectal nucleus of the optic tract and the dorsal terminal nucleus of the accessory optic system than properties of neurons in the visual cortex.

UI	MeSH Term	Description	Entries
D007839	Functional Laterality	Behavioral manifestations of cerebral dominance in which there is preferential use and superior functioning of either the left or the right side, as in the preferred use of the right hand or right foot.	Ambidexterity,Behavioral Laterality,Handedness,Laterality of Motor Control,Mirror Writing,Laterality, Behavioral,Laterality, Functional,Mirror Writings,Motor Control Laterality,Writing, Mirror,Writings, Mirror
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D003290	Convergence, Ocular	The turning inward of the lines of sight toward each other.	Convergences, Ocular,Ocular Convergence,Ocular Convergences
D004585	Electrooculography	Recording of the average amplitude of the resting potential arising between the cornea and the retina in light and dark adaptation as the eyes turn a standard distance to the right and the left. The increase in potential with light adaptation is used to evaluate the condition of the retinal pigment epithelium.	EOG,Electrooculograms,Electrooculogram
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013285	Strabismus	Misalignment of the visual axes of the eyes. In comitant strabismus the degree of ocular misalignment does not vary with the direction of gaze. In noncomitant strabismus the degree of misalignment varies depending on direction of gaze or which eye is fixating on the target. (Miller, Walsh & Hoyt's Clinical Neuro-Ophthalmology, 4th ed, p641)	Concomitant Strabismus,Dissociated Horizontal Deviation,Dissociated Vertical Deviation,Heterophoria,Heterotropias,Hypertropia,Non-Concomitant Strabismus,Nonconcomitant Strabismus,Phorias,Squint,Strabismus, Comitant,Strabismus, Noncomitant,Convergent Comitant Strabismus,Mechanical Strabismus,Comitant Strabismus,Comitant Strabismus, Convergent,Deviation, Dissociated Horizontal,Dissociated Horizontal Deviations,Dissociated Vertical Deviations,Heterophorias,Heterotropia,Horizontal Deviation, Dissociated,Hypertropias,Non Concomitant Strabismus,Noncomitant Strabismus,Phoria,Strabismus, Concomitant,Strabismus, Convergent Comitant,Strabismus, Mechanical,Strabismus, Non-Concomitant,Strabismus, Nonconcomitant
D014793	Visual Cortex	Area of the OCCIPITAL LOBE concerned with the processing of visual information relayed via VISUAL PATHWAYS.	Area V2,Area V3,Area V4,Area V5,Associative Visual Cortex,Brodmann Area 18,Brodmann Area 19,Brodmann's Area 18,Brodmann's Area 19,Cortical Area V2,Cortical Area V3,Cortical Area V4,Cortical Area V5,Secondary Visual Cortex,Visual Cortex Secondary,Visual Cortex V2,Visual Cortex V3,Visual Cortex V3, V4, V5,Visual Cortex V4,Visual Cortex V5,Visual Cortex, Associative,Visual Motion Area,Extrastriate Cortex,Area 18, Brodmann,Area 18, Brodmann's,Area 19, Brodmann,Area 19, Brodmann's,Area V2, Cortical,Area V3, Cortical,Area V4, Cortical,Area V5, Cortical,Area, Visual Motion,Associative Visual Cortices,Brodmanns Area 18,Brodmanns Area 19,Cortex Secondary, Visual,Cortex V2, Visual,Cortex V3, Visual,Cortex, Associative Visual,Cortex, Extrastriate,Cortex, Secondary Visual,Cortex, Visual,Cortical Area V3s,Extrastriate Cortices,Secondary Visual Cortices,V3, Cortical Area,V3, Visual Cortex,V4, Area,V4, Cortical Area,V5, Area,V5, Cortical Area,V5, Visual Cortex,Visual Cortex Secondaries,Visual Cortex, Secondary,Visual Motion Areas
D015348	Vision, Binocular	The blending of separate images seen by each eye into one composite image.	Binocular Vision
D017120	Nystagmus, Optokinetic	Normal nystagmus produced by looking at objects moving across the field of vision.	Optokinetic Nystagmus