title: Source of high-frequency oscillations in oblique saccade trajectory.
abstract: Most common eye movements, oblique saccades, feature rapid velocity, precise amplitude, but curved trajectory that is variable from trial-to-trial. In addition to curvature and inter-trial variability, the oblique saccade trajectory also features high-frequency oscillations. A number of studies proposed the physiological basis of the curvature and inter-trial variability of the oblique saccade trajectory, but kinematic characteristics of high-frequency oscillations are yet to be examined. We measured such oscillations and compared their properties with orthogonal pure horizontal and pure vertical oscillations generated during pure vertical and pure horizontal saccades, respectively. We found that the frequency of oscillations during oblique saccades ranged between 15 and 40 Hz, consistent with the frequency of orthogonal saccadic oscillations during pure horizontal or pure vertical saccades. We also found that the amplitude of oblique saccade oscillations was larger than pure horizontal and pure vertical saccadic oscillations. These results suggest that the superimposed high-frequency sinusoidal oscillations upon the oblique saccade trajectory represent reverberations of disinhibited circuit of reciprocally innervated horizontal and vertical burst generators.
authors.affiliation: Cole Eye Institute, Cleveland Clinic Foundation, 2022 E 105th Street, Cleveland, OH 44106, USA. Electronic address: fatemaghasia@gmail.com.
authors.forename: Fatema F
authors.initials: FF
authors.lastname: Ghasia
authors.affiliation: Department of Neurology, Emory University, Atlanta, GA, USA.
authors.forename: Aasef G
authors.initials: AG
authors.lastname: Shaikh
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D053483:Eye Movement Measurements; D006801:Humans; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000502:physiology; D012438:Saccades / Q000502:physiology*
keywords: burst neuron; eye movement; omnipause neuron; post-inhibitory rebound; reciprocal innervation