当前位置： SCI文献检索 > INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE期刊下所有文献 > Responses of medial rectus motoneurons in monkeys with strabismus.

Responses of medial rectus motoneurons in monkeys with strabismus.

Abstract：

PURPOSE:Monkeys reared under conditions of alternating monocular occlusion during their first few months of life show large horizontal strabismus, "A" patterns, and dissociated vertical deviation. "A" patterns manifest as an inappropriate horizontal component in the deviated eye during vertical eye movements (cross-axis movement). The objective of this study was to investigate response properties of medial rectus motoneurons (MRMNs) in relation to strabismus properties. METHODS:Burst-tonic activity of 21 MRMNs in the oculomotor nucleus were recorded from two monkeys with exotropia as they performed horizontal and vertical smooth pursuit (0.2 Hz, ±10°) under monocular viewing conditions. Neuronal responses and horizontal component of eye movements were used to identify regression coefficients in a first-order model for each tracking condition. RESULTS:Comparison of position, velocity, and constant parameter coefficients, estimated from horizontal tracking data with either eye viewing, showed no significant differences (P > 0.07), indicating that neuronal activity could account for the horizontal misalignment. Comparison of the position, velocity, and constant parameter coefficients estimated from horizontal tracking and the cross-axis condition showed no significant differences (P > 0.07), suggesting that motoneuron activity could account for most of the inappropriate horizontal cross-axis movement observed in the covered eye during vertical smooth pursuit. CONCLUSIONS:These data suggest that, in animals with sensory-induced strabismus, central innervation to extraocular muscles is responsible for setting the state of strabismus. Mechanical factors such as muscle length adaptation (for horizontal misalignment) and pulley heterotopy or static torsion (for "A" patterns) likely do not play a major role in determining properties in a sensory-induced strabismus.

journal_name

Invest Ophthalmol Vis Sci

journal_title

Investigative ophthalmology & visual science

authors

Joshi AC,Das VE

doi

10.1167/iovs.11-7402

subject

Has Abstract

pub_date

2011-08-24 00:00:00

pages

6697-705

issue

eissn

0146-0404

issn

1552-5783

pii

iovs.11-7402

journal_volume

pub_type

杂志文章

在线工具

Responses of medial rectus motoneurons in monkeys with strabismus.