Missing Lateral Rectus Force and Absence of Medial Rectus Co-Contraction in Ocular Convergence
| Autor: | Christopher J. Bockisch, Joel M. Miller, Dmitri S. Pavlovski |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Motor Neurons
Physics Vision Binocular genetic structures Physiology General Neuroscience Muscle Fibers Skeletal Anatomy Convergence Ocular Macaca mulatta Co contraction Ocular physiology medicine.anatomical_structure Oculomotor Muscles Muscle Tonus Ocular convergence Saccades medicine Animals Orbit (anatomy) |
| Zdroj: | Journal of Neurophysiology. 87:2421-2433 |
| ISSN: | 1522-1598 0022-3077 |
| DOI: | 10.1152/jn.00566.2001 |
| Popis: | For a given position of the eye in the orbit, most abducens motoneurons (LRMNs) fire at higher rates in converged gaze than when convergence is relaxed, implying that lateral rectus (LR) muscle force will be higher for a given eye position in convergence. If medial rectus (MR) muscle force balances LR force, it too would be higher in convergence, that is, LRMN recording studies predict horizontal rectus co-contraction in convergence. Three trained rhesus monkeys with binocular eye coils and custom muscle force transducers (MFTs) on LR and MR of one eye alternately fixated near (approximately 7 cm) and far (200 cm) targets with vergence movements of 20–30°. Tonic muscle forces were also measured during conjugate fixation of far targets over a 30 × 30° field. MFT characteristics and effects on oculomotility were assessed. Contrary to predictions, we found small ( |
| Databáze: | OpenAIRE |
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