HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 90/6/3838    most recent 00858.2002v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (11) Citing Articles via Google Scholar Google Scholar Articles by Busettini, C. Articles by Mays, L. E. Search for Related Content PubMed PubMed Citation Articles by Busettini, C. Articles by Mays, L. E.

Pontine Omnipause Activity During Conjugate and Disconjugate Eye Movements in Macaques

Department of Physiological Optics and Vision Science Research Center, University of Alabama at Birmingham, Birmingham, Alabama 35294

Submitted 25 September 2002; accepted in final form 16 August 2003

Previous reports have shown that saccades executed during vergence eye movements are often slower and longer than conjugate saccades. Lesions in the nucleus raphe interpositus, where pontine omnipause neurons (OPNs) are located, were also shown to result in slower and longer saccades. If vergence transiently suppresses the activity of the OPNs just before a saccade, then reduced presaccadic activity might mimic the behavioral effects of a lesion. To test this hypothesis, 64 OPNs were recorded from 7 alert rhesus monkeys during smooth vergence and saccades with and without vergence. The firing rate of many OPNs was modulated by static vergence angle but not by version and showed transient changes during slow vergence without saccades. This modulation was smooth, and not the abrupt pause seen for saccades, indicating that OPNs do not act as gates for vergence commands. We confirmed that saccades made during both convergence and divergence are significantly slower and longer than conjugate saccades. OPNs paused for all saccades, and the pause lead (interval between pause onset and saccadic onset) was significantly longer for saccades with convergence, in agreement with our hypothesis. Contrary to our hypothesis, pause lead was not longer for saccades with divergence, even though these saccades were slowed as much as those occurring during convergence. Furthermore, there was no significant correlation, on a trial-by-trial basis, between pause lead and saccadic slowing. These results suggest that it is unlikely that presaccadic slowing of OPNs is responsible for the slower saccades seen during vergence movements.

This article has been cited by other articles:

				M. R. Van Horn, P. A. Sylvestre, and K. E. Cullen The Brain Stem Saccadic Burst Generator Encodes Gaze in Three-Dimensional Space J Neurophysiol, May 1, 2008; 99(5): 2602 - 2616. [Abstract] [Full Text] [PDF]

				K. Arnoldi and J. D. Reynolds A Review of Convergence Insufficiency: What Are We Really Accomplishing with Exercises? Amer. Orthoptic Jrnl., January 1, 2007; 57(1): 123 - 130. [Abstract] [PDF]

				S. Ramat, R. J. Leigh, D. S. Zee, and L. M. Optican What clinical disorders tell us about the neural control of saccadic eye movements Brain, January 1, 2007; 130(1): 10 - 35. [Abstract] [Full Text] [PDF]

				C. Busettini and L. E. Mays Saccade-Vergence Interactions in Macaques. I. Test of the Omnipause Multiply Model J Neurophysiol, October 1, 2005; 94(4): 2295 - 2311. [Abstract] [Full Text] [PDF]

				C. Busettini and L. E. Mays Saccade-Vergence Interactions in Macaques. II. Vergence Enhancement as the Product of a Local Feedback Vergence Motor Error and a Weighted Saccadic Burst J Neurophysiol, October 1, 2005; 94(4): 2312 - 2330. [Abstract] [Full Text] [PDF]

				A. N. Kumar, Y. Han, L. F. Dell'osso, D. M. Durand, and R. J. Leigh Directional Asymmetry During Combined Saccade-Vergence Movements J Neurophysiol, May 1, 2005; 93(5): 2797 - 2808. [Abstract] [Full Text] [PDF]