Passive eye movements induced by electromagnetic force(EMF) in rats  

作　　者：Yue Yu Jun Huang Chun-Ming Zhang Tian-Wen Chen David S.Sandlin Shao-Xun Wang Alberto A.Arteaga Jerome Allison Yang Ou Susan Warren Paul May Hong Zhu Wu Zhou 

机构地区：[1]Departments of Otolaryngology and Communicative Sciences,University of Mississippi Medical Center,Jackson MS 39216,USA [2]Department of Otolaryngology,First Affiliated Hospital,Shanxi Medical University,Taiyuan Shanxi 030001,China [3]MD/PhD Program,University of Mississippi Medical Center,Jackson MS 39216,USA [4]Pharmacology and Toxicology,University of Mississippi Medical Center,Jackson MS 39216.USA [5]Neurobiology and Anatomical Sciences,University of Mississippi Medical Center,Jackson MS 39216,USA [6]Neurology,University of Mississippi Medical Center,Jackson MS 39216,USA

出　　处：《Zoological Research》2019年第3期211-218,共8页动物学研究（英文）

基　　金：supported by NIH grants to WZ(R21EY025550; R01DC014930)and HZ(R01DC012060)

摘　　要：Accurate information on eye position in the orbit is available from visual feedback,efference copy of the oculomotor commands and proprioceptive signals from the extraocular muscles (EOM).Whereas visual feedback and oculomotor commands have been extensively studied,central processing of EOM proprioceptive signals remains to be elucidated.A challenge to the field is to develop an approach to induce passive eye movements without physically contacting the eyes.A novel method was developed to generate passive eye movements in rats.A small rare-earth magnet disk (0.7 mm diameter,0.5 mm thickness) was attached to the surface of a rat's eyeball.A metal rod (5 mm diameter) wrapped with an electromagnetic (EM) coil was placed near the magnet (8-15 mm).By passing currents to the EM coil,electromagnetic force (EMF) was generated and acted upon the magnet and induced passive eye movements.The EMF induced well-defined passive eye movements,whose directions were dependent on current polarity and amplitudes and peak velocities were dependent on current intensity and duration.Peak velocities of the EMF-induced eye movements were linearly related to amplitudes,exhibiting main sequence relationships similar to that of saccades in awake rats and eye movements induced by electrical microstimulation of the abducens nucleus in anesthetized rats.Histological examination showed that repetitive EMF stimulations did not appear to result in damages in the EOM fibers.These results validated the EMF approach as a novel tool to investigate EOM proprioceptive signals and their roles in visual localization and gaze control.Accurate information on eye position in the orbit is available from visual feedback, efference copy of the oculomotor commands and proprioceptive signals from the extraocular muscles(EOM). Whereas visual feedback and oculomotor commands have been extensively studied, central processing of EOM proprioceptive signals remains to be elucidated. A challenge to the field is to develop an approach to induce passive eye movements without physically contacting the eyes. A novel method was developed to generate passive eye movements in rats. A small rare-earth magnet disk(0.7 mm diameter, 0.5 mm thickness) was attached to the surface of a rat’s eyeball. A metal rod(5 mm diameter) wrapped with an electromagnetic(EM) coil was placed near the magnet(8–15 mm). By passing currents to the EM coil, electromagnetic force(EMF) was generated and acted upon the magnet and induced passive eye movements. The EMF induced well-defined passive eye movements, whose directions were dependent on current polarity and amplitudes and peak velocities were dependent on current intensity and duration. Peak velocities of the EMF-induced eye movements were linearly related to amplitudes,exhibiting main sequence relationships similar to that of saccades in awake rats and eye movements induced by electrical microstimulation of the abducens nucleus in anesthetized rats. Histological examination showed that repetitive EMF stimulations did not appear to result in damages in the EOM fibers. These results validated the EMF approach as a novel tool to investigate EOM proprioceptive signals and their roles in visual localization and gaze control.

关 键 词：Eye MOVEMENT PROPRIOCEPTION EXTRAOCULAR muscles STRETCH REFLEX 

分 类 号：Q[生物学]