Journal of Neurophysiology, Vol 58, Issue 2 300-318, Copyright © 1987 by APS

ARTICLES

Eye movements induced by pontine stimulation: interaction with visually triggered saccades

D. L. Sparks, L. E. Mays and J. D. Porter
Department of Physiology and Biophysics, University of Alabama at Birmingham 35294.

1. Rhesus monkeys were trained to look to brief visual targets presented in an otherwise darkened room. On some trials, after the visual target was extinguished but before a saccade to it could be initiated, the eyes were driven to another orbital position by microstimulation of the paramedian pontine reticular formation. If, as current models of the saccadic system suggest, a copy of the motor command is used as a feedback signal of eye position, failure to compensate for stimulation-induced movements would indicate that stimulation occurred at a site beyond the point from which the eye position signal was derived. 2. Animals compensated for perturbations of eye position induced by stimulation of most pontine sites by making saccades that directed gaze to the position of the visual target. With stimulation at other pontine sites, compensatory saccades did not occur. 3. Pontine stimulation sometimes triggered, prematurely, impending visually directed saccades. The direction and amplitude of the premature movement depended upon the location of the briefly presented visual target. The amplitude of the premature movement was also a function of the interval between the stimulation train and the impending saccade. These data suggest that input signals for the horizontal and vertical pulse/step generators develop gradually during the presaccadic interval. Saccade trigger signals need to be delayed until the formation of these signals is completed. 4. The implications of these findings for models of the saccadic system are discussed. Robinson's local feedback model of the saccadic system can explain compensation for pontine stimulation-induced changes in eye position but cannot easily account for the failure to compensate for perturbations in eye position produced by stimulation at other sites. Modified versions of Robinson's model, which assume that the input signal to the pulse/step generator is the desired displacement of the eye, can account for both compensation and the failure to compensate since two separate neural integrators are employed. However, these models ignore kinematic arguments that commands to the extraocular muscles must specify the absolute position of the eye in the orbit rather than a relative movement from a previous position.

This article has been cited by other articles:

				D. L. Kimmel and T. Moore Temporal Patterning of Saccadic Eye Movement Signals J. Neurosci., July 18, 2007; 27(29): 7619 - 7630. [Abstract] [Full Text] [PDF]

				E. M. Klier, D. E. Angelaki, and B. J. M. Hess Roles of Gravitational Cues and Efference Copy Signals in the Rotational Updating of Memory Saccades J Neurophysiol, July 1, 2005; 94(1): 468 - 478. [Abstract] [Full Text] [PDF]

				Y. IZAWA, H. SUZUKI, and Y. SHINODA Initiation and Suppression of Saccades by the Frontal Eye Field in the Monkey Ann. N.Y. Acad. Sci., April 1, 2005; 1039(1): 220 - 231. [Abstract] [Full Text] [PDF]

				Y. Izawa, H. Suzuki, and Y. Shinoda Suppression of Visually and Memory-Guided Saccades Induced by Electrical Stimulation of the Monkey Frontal Eye Field. I. Suppression of Ipsilateral Saccades J Neurophysiol, October 1, 2004; 92(4): 2248 - 2260. [Abstract] [Full Text] [PDF]

				Y. Izawa, H. Suzuki, and Y. Shinoda Suppression of Visually and Memory-Guided Saccades Induced by Electrical Stimulation of the Monkey Frontal Eye Field. II. Suppression of Bilateral Saccades J Neurophysiol, October 1, 2004; 92(4): 2261 - 2273. [Abstract] [Full Text] [PDF]

				C. Busettini and L. E. Mays Pontine Omnipause Activity During Conjugate and Disconjugate Eye Movements in Macaques J Neurophysiol, December 1, 2003; 90(6): 3838 - 3853. [Abstract] [Full Text] [PDF]

				E. J. Barton, J. S. Nelson, N. J. Gandhi, and D. L. Sparks Effects of Partial Lidocaine Inactivation of the Paramedian Pontine Reticular Formation on Saccades of Macaques J Neurophysiol, July 1, 2003; 90(1): 372 - 386. [Abstract] [Full Text] [PDF]

				J. W. Gnadt, M. E. Jackson, and O. Litvak Analysis of the Frequency Response of the Saccadic Circuit: System Behavior J Neurophysiol, August 1, 2001; 86(2): 724 - 740. [Abstract] [Full Text] [PDF]

				H.H.L.M. Goossens and A. J. Van Opstal Blink-Perturbed Saccades in Monkey. I. Behavioral Analysis J Neurophysiol, June 1, 2000; 83(6): 3411 - 3429. [Abstract] [Full Text] [PDF]

				T. L. Alvarez, J. L. Semmlow, and W. Yuan Closely Spaced, Fast Dynamic Movements in Disparity Vergence J Neurophysiol, January 1, 1998; 79(1): 37 - 44. [Abstract] [Full Text] [PDF]

				J. D. Crawford and D. Guitton Visual-Motor Transformations Required for Accurate and Kinematically Correct Saccades J Neurophysiol, September 1, 1997; 78(3): 1447 - 1467. [Abstract] [Full Text] [PDF]

				C. Quaia and L. M. Optican Model With Distributed Vectorial Premotor Bursters Accounts for the Component Stretching of Oblique Saccades J Neurophysiol, August 1, 1997; 78(2): 1120 - 1134. [Abstract] [Full Text] [PDF]

				D. D. Burman and C. J. Bruce Suppression of Task-Related Saccades by Electrical Stimulation in the Primate's Frontal Eye Field J Neurophysiol, May 1, 1997; 77(5): 2252 - 2267. [Abstract] [Full Text] [PDF]