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Query: UMLS:C0038379 (strabismus)
 9,317 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Visual response properties of neurons in the nucleus of the optic tract (NOT) and dorsal terminal nucleus of the accessory optic tract (DTN) were electrophysiologically investigated in five congenitally strabismic cats and compared with normal adult cats and 3- to 4-wk-old kittens. 2. As in normal cats, NOT-DTN cells of strabismic cats preferred horizontal ipsiversive stimulus movement. However, NOT-DTN neurons in strabismic cats altered their activity to a lesser amount per degree change of stimulus direction than do normal adult cats. In addition, NOT-DTN cells in strabismic cats exhibited a broader directional tuning, i.e., they increase their activity to a broader range of directions than control NOT-DTN cells. 3. Spontaneous activity and activity difference between preferred and nonpreferred direction were significantly lower in NOT-DTN neurons of strabismic cats than in normal adult cats and resembled that found in 3-wk-old kittens. Maximal stimulus-related activity was lower than in normal adult cats but higher than in kittens. 4. Visual latencies to onset of movement in the preferred direction were indistinguishable in strabismic and in normal adult cats. Visual latencies to onset of movement in the nonpreferred direction, however, were shorter in strabismic cats than in normal adult cats. 5. The average velocity tuning curve of NOT-DTN cells in strabismic cats was very flat without a well-defined optimal stimulus velocity. Thus it closely resembled data from 3-wk-old kittens. 6. Binocular convergence was significantly altered to a stronger dominance of the contralateral eye in NOT-DTN of strabismic cats. This reduction of binocular neurons was less pronounced than in cats with artificially induced strabismus or in 3-wk-old kittens. 7. In conclusion, the data presented here for retinal slip neurons in the NOT-DTN of strabismic cats closely resemble those from 3-wk-old kittens where no functional cortical input to the NOT-DTN is present. However, the elevated stimulus-driven activity and the still relatively high degree of binocularity give a clear indication of a functional, albeit weak and abnormal, cortical input to the NOT-DTN in these naturally strabismic cats.
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PMID:Retinal slip neurons in the nucleus of the optic tract and dorsal terminal nucleus in cats with congenital strabismus. 872 92

The optokinetic reflex and neuronal response properties in the central visual pathway were studied in three macaque monkeys (Macaca nemestrina) with early childhood strabismus of various origin. Binocularity in the primary visual cortex (VI) measured electrophysiologically was reduced both in a monkey with resolved strabismus and in a monkey with accommodative strabismus when compared to normal controls. By contrast, binocularity in the nucleus of the optic tract and dorsal terminal nucleus of the accessory optic system (NOT-DTN) was only reduced in the monkey with resolved strabismus ('resolved'), but appeared normal in animals with accommodative strabismus ('accom. 1 'and 'accom. 2'). Sub-threshold binocular interactions were normal in all animals. The velocity tuning curves of retinal slip neurons in the NOT-DTN of all strabismic monkeys were not different from normal controls. Horizontal optokinetic nystagmus was asymmetric in monkey 'accom. 2', and for the non-fixating eye in monkey 'resolved'. In monkey 'accom. 1' OKN was normal. Open loop eye velocity was lower in the monkey with resolved strabismus than in monkeys with accommodative strabismus. These data suggest that different causes of strabismus may affect neuronal response properties and behavior to different degrees. The effects on the optokinetic reflex of resolved, but early onset strabismus were more severe than those of accommodative strabismus. This corresponds to the wide variability of defects in the optokinetic system of strabismic humans.
Strabismus 1996
PMID:Neuronal basis of optokinetic reflex pathology in naturally strabismic monkeys. 2131 6