Journal of Neurophysiology, Vol 76, Issue 2 908-926, Copyright © 1996 by APS

ARTICLES

Activity of visuomotor burst neurons in the superior colliculus accompanying express saccades

J. A. Edelman and E. L. Keller
Graduate Group in Bioengineering, University of California at Berkeley 94720, USA.

1. We recorded visuomotor burst neurons in the deeper layers of the superior colliculus while two monkeys (Macaca fascicularis) made short-latency saccades known as express saccades to visual targets in order to determine whether the visual discharge normally seen for these cells served as the premotor burst during express saccades. We then compared saccade-related activity during express saccades with that recorded during regular latency saccades and delayed saccades. 2. Saccade latency histograms for two monkeys during trials with a temporal gap between fixation-point offset and target onset showed a distinct peak of saccades around 70-80 ms. One monkey also showed an additional peak around 125 ms. 3. Express saccades were found on the average to have the same relationship of saccade peak velocity to saccade amplitude as regular latency saccades and delayed saccades. Express saccades tended to be somewhat more hypometric than the other classes of saccades. However, express saccades were clearly visually guided and not anticipatory responses. 4. For most cells studied (33/40), express saccades were accompanied by a single, uninterrupted burst of activity beginning 40-50 ms after target onset and continuing until sometime around the end of the saccade. For a smaller group of cells (7/40), two peaks of burst activity were seen, although the second peak was smaller and tended to occur late, after saccade onset. Across all cells, the peak of visuomotor cell activity during express saccades correlated just as well with target onset as it did with saccade onset. 5. When considered as discharge temporally aligned to the onset of the saccade, bursts accompanying express saccades tended to begin at approximately the same time as that for regular and delayed saccades. However, this discharge generally peaked earlier for express than for regular and delayed saccades. Also, the magnitude of discharge for express saccades was higher than that for delayed saccades throughout the burst. 6. When considered as discharge temporally aligned to the appearance of the target, bursts began earlier for express and regular saccade trials than for delayed saccade trials. Peak discharge tended to be greater for express saccades than for the other classes of saccades. 7. The results of this investigation are consistent with the suggestion that the visual burst of visuomotor neurons in the deeper layers of the superior colliculus plays a role in the initiation of express saccades similar to that played by the premotor burst for saccades of longer latency. The elevated discharge for express saccades supports the idea that the superior colliculus plays a more critical role in express saccade generation than in the generation of longer-latency saccades. The elevated discharge also suggests that visuomotor bursters do not code one-to-one for saccade velocity nor for saccade dynamic motor error.

This article has been cited by other articles:

				R. A. Marino, C. K. Rodgers, R. Levy, and D. P. Munoz Spatial Relationships of Visuomotor Transformations in the Superior Colliculus Map J Neurophysiol, November 1, 2008; 100(5): 2564 - 2576. [Abstract] [Full Text] [PDF]

				M. C. Dorris, E. Olivier, and D. P. Munoz Competitive Integration of Visual and Preparatory Signals in the Superior Colliculus during Saccadic Programming J. Neurosci., May 9, 2007; 27(19): 5053 - 5062. [Abstract] [Full Text] [PDF]

				C. K. Rodgers, D. P. Munoz, S. H. Scott, and M. Pare Discharge Properties of Monkey Tectoreticular Neurons J Neurophysiol, June 1, 2006; 95(6): 3502 - 3511. [Abstract] [Full Text] [PDF]

				O. A. Coubard and Z. Kapoula Dorsolateral Prefrontal Cortex Prevents Short-latency Saccade and Vergence: a TMS Study Cereb Cortex, March 1, 2006; 16(3): 425 - 436. [Abstract] [Full Text] [PDF]

				M. Pare and D. P. Hanes Controlled Movement Processing: Superior Colliculus Activity Associated with Countermanded Saccades J. Neurosci., July 23, 2003; 23(16): 6480 - 6489. [Abstract] [Full Text] [PDF]

				T. P. Doubell, I. Skaliora, J. Baron, and A. J. King Functional Connectivity between the Superficial and Deeper Layers of the Superior Colliculus: An Anatomical Substrate for Sensorimotor Integration J. Neurosci., July 23, 2003; 23(16): 6596 - 6607. [Abstract] [Full Text] [PDF]

				R. J. Krauzlis Neuronal Activity in the Rostral Superior Colliculus Related to the Initiation of Pursuit and Saccadic Eye Movements J. Neurosci., May 15, 2003; 23(10): 4333 - 4344. [Abstract] [Full Text] [PDF]

				R. M. McPeek and E. L. Keller Saccade Target Selection in the Superior Colliculus During a Visual Search Task J Neurophysiol, October 1, 2002; 88(4): 2019 - 2034. [Abstract] [Full Text] [PDF]

				R. M. McPeek and E. L. Keller Superior Colliculus Activity Related to Concurrent Processing of Saccade Goals in a Visual Search Task J Neurophysiol, April 1, 2002; 87(4): 1805 - 1815. [Abstract] [Full Text] [PDF]

				E. M. Reingold and D. M. Stampe Saccadic Inhibition in Voluntary and Reflexive Saccades J. Cogn. Neurosci., April 1, 2002; 14(3): 371 - 388. [Abstract] [Full Text] [PDF]

				J. A. Edelman and M. E. Goldberg Dependence of Saccade-Related Activity in the Primate Superior Colliculus on Visual Target Presence J Neurophysiol, August 1, 2001; 86(2): 676 - 691. [Abstract] [Full Text] [PDF]

				T. P. Trappenberg, M. C. Dorris, D. P. Munoz, and R. M. Klein A Model of Saccade Initiation Based on the Competitive Integration of Exogenous and Endogenous Signals in the Superior Colliculus J. Cogn. Neurosci., March 1, 2001; 13(2): 256 - 271. [Abstract] [Full Text] [PDF]

				E. L. Keller, R. M. McPeek, and T. Salz Evidence Against Direct Connections to PPRF EBNs From SC in the Monkey J Neurophysiol, September 1, 2000; 84(3): 1303 - 1313. [Abstract] [Full Text] [PDF]

				D. M. Waitzman, V. L. Silakov, S. DePalma-Bowles, and A. S. Ayers Effects of Reversible Inactivation of the Primate Mesencephalic Reticular Formation. I. Hypermetric Goal-Directed Saccades J Neurophysiol, April 1, 2000; 83(4): 2260 - 2284. [Abstract] [Full Text] [PDF]

				S. Everling and D. P. Munoz Neuronal Correlates for Preparatory Set Associated with Pro-Saccades and Anti-Saccades in the Primate Frontal Eye Field J. Neurosci., January 1, 2000; 20(1): 387 - 400. [Abstract] [Full Text] [PDF]

				H. Aizawa, Y. Kobayashi, M. Yamamoto, and T. Isa Injection of Nicotine Into the Superior Colliculus Facilitates Occurrence of Express Saccades in Monkeys J Neurophysiol, September 1, 1999; 82(3): 1642 - 1646. [Abstract] [Full Text] [PDF]

				S. Everling, M. C. Dorris, R. M. Klein, and D. P. Munoz Role of Primate Superior Colliculus in Preparation and Execution of Anti-Saccades and Pro-Saccades J. Neurosci., April 1, 1999; 19(7): 2740 - 2754. [Abstract] [Full Text] [PDF]

				M. A. Basso and R. H. Wurtz Modulation of Neuronal Activity in Superior Colliculus by Changes in Target Probability J. Neurosci., September 15, 1998; 18(18): 7519 - 7534. [Abstract] [Full Text] [PDF]

				J. A. Edelman and E. L. Keller Dependence on Target Configuration of Express Saccade-Related Activity in the Primate Superior Colliculus J Neurophysiol, September 1, 1998; 80(3): 1407 - 1426. [Abstract] [Full Text] [PDF]

				S. Everling, M. C. Dorris, and D. P. Munoz Reflex Suppression in the Anti-Saccade Task Is Dependent on Prestimulus Neural Processes J Neurophysiol, September 1, 1998; 80(3): 1584 - 1589. [Abstract] [Full Text] [PDF]

				S. Everling, M. Pare, M. C. Dorris, and D. P. Munoz Comparison of the Discharge Characteristics of Brain Stem Omnipause Neurons and Superior Colliculus Fixation Neurons in Monkey: Implications for Control of Fixation and Saccade Behavior J Neurophysiol, February 1, 1998; 79(2): 511 - 528. [Abstract] [Full Text] [PDF]

				P. H. Lee, M. C. Helms, G. J. Augustine, and W. C. Hall Role of intrinsic synaptic circuitry in collicular sensorimotor integration PNAS, November 25, 1997; 94(24): 13299 - 13304. [Abstract] [Full Text] [PDF]

				M. C. Dorris, M. Pare, and D. P. Munoz Neuronal Activity in Monkey Superior Colliculus Related to the Initiation of Saccadic Eye Movements J. Neurosci., November 1, 1997; 17(21): 8566 - 8579. [Abstract] [Full Text] [PDF]