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Activity of the brain stem omnipause neurons during saccades perturbed by stimulation of the primate superior colliculus


, : Activity of the brain stem omnipause neurons during saccades perturbed by stimulation of the primate superior colliculus. Journal of Neurophysiology 82(6): 3254-3267

Stimulation of the rostral approximately 2 mm of the superior colliculus (SC) during a large, visual target-initiated saccade produces a spatial deviation of the ongoing saccade and then stops it in midflight. After the termination of the stimulation, the saccade resumes and ends near the location of the flashed target. The density of collicular projections to the omnipause neuron (OPN) region is greatest from the rostral SC and decreases gradually for the more caudal regions. It has been hypothesized that the microstimulation excites the OPNs through these direct connections, and the reactivation of OPNs, which are normally silent during saccades, stops the initial component in midflight by gating off the saccadic burst generator. Two predictions emerge from this hypothesis: 1) for microstimulation triggered on the onset of large saccades, the time from stimulation onset to resumption of OPN discharge should decrease as the stimulation site is moved rostral and 2) the lead time from reactivation of OPNs to the end of the initial saccade on stimulation trials should be equal to the lead time of pause end with respect to the end of control saccades. We tested this hypothesis by recording OPN activity during saccades perturbed by stimulation of the rostral approximately 2 mm of the SC. The distance of the stimulation site from the most rostral extent of the SC and the time of reactivation with respect to stimulation onset were not significantly correlated. The mean lead of reactivation of OPNs relative to the end of the initial component of perturbed saccades (6.5 ms) was significantly less than the mean lead with respect to the end of control (9.6 ms) and resumed saccades (10.4 ms). These results do not support the notion that the excitatory input from SC neurons-in particular, the fixation neurons in the rostral SC-provide the major signal to reactivate OPNs and end saccades. An alternative, conceptual model to explain the temporal sequence of events induced by stimulation of the SC during large saccades is presented. Other OPN activity parameters also were measured and compared for control and stimulation conditions. The onset of pause with respect to resumed saccade onset was larger and more variable than the onset of pause with respect to control saccades, whereas pause end with respect to the end of resumed and control saccades was similar. The reactivated discharge of OPNs during the period between the end of the initial and the onset of the resumed saccades was at least as strong as that following control movements. This latter observation is interpreted in terms of the resettable neural integrator hypothesis.

US$29.90

PMID: 10601458


Other references

Braun, H.; Pinker, H., 1951: On the therapy of cases of actinomycosis refractory to Rontgen rays, with special reference to penicillin treatment. Following a discussion of reports in the relevant literature on the therapy of actinomycosis (Actinomyces), with special reference to penicillin, the authors report successful results with the drug from the Medical Clinic of Wurzburg University in...

Lang, E.; Ruffo, A.; Goffrini, P.; Castelli, D., 1952: An experimental study on the pathogenesis of valvular lesions accompanying interatrial and interventricular communication. Minerva Chirurgica 7(2): 67-77

Ti, H-Hui.; Lin, L-Dong.; Ding, W-Bing.; Wei, X-Yi., 2012: A new flavan-3-ol from Artocarpus nitidus subsp. lingnanensis. Further investigation on the stems of Artocarpus nitidus subsp. lingnanensis led to the isolation and characterization of a new flavan-3-ol, named artoflavanocoumarin (1), along with three known compounds (+)-catechin , (+)-afzelechin 3-O-?-l-rham...

Babani, F.; Lichtenthaler, H.K., 2000: Fluorescence signatures of wheat genotypes at high temperature and high irradiance. Plant Physiology & Biochemistry (Paris) 38(Supplement): s205, August

Yang, M.U.; Yaroslavsky, A.N.; Farinelli, W.A.; Flotte, T.J.; Rius-Diaz, F.; Tsao, S.S.; Anderson, R.Rox., 2005: Long-pulsed neodymium:yttrium-aluminum-garnet laser treatment for port-wine stains. Laser treatment of port-wine stain (PWS) might be improved using a deeply penetrating wavelength. PWSs in 17 patients were treated 3 times with a 595-nm pulsed dye laser (PDL) and a 1064-nm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser. Fluence...

Ishigami, M.; Furuhashi, K., 1997: Effects of CICR on the cyclic contraction-relaxation of Physarum plasmodium. Cell Structure & Function 22(6): 705, Dec

Kosik J., 1967: Dynamics of soil moisture under winter wheat m spring barley m maize m for grain and sugar beet d in the years 1962 1965. Vedecke Prace Vyskumneho Ustavu Rastlinnej Vyroby v Piestanoch (5): 141-155

Markell, Ek, 1984: In memoriam Marietta Voge 1918-1984. Journal of parasitology 70(6): 977

Karl W., 1975: Investigations on metabolites of microorganisms part 8 aldgamycin f a new antibiotic from streptomyces lavendulae. Chemische Berichte: 780-789

van Hulst, M.; Sagoe, K.W.C.; Vermande, J.E.; van der Schaaf, I.P.; van der Tuuk Adriani, W.P.A.; Torpey, K.; Ansah, J.; Mingle, J.A.A.; Smit Sibinga, C.Th.; Postma, M.J., 2008: Cost-effectiveness of HIV screening of blood donations in Accra (Ghana). Areas with high HIV-incidence rates compared to the developed world may benefit from additional testing in blood banks and may show more favorable cost-effectiveness ratios. We evaluated the cost-effectiveness of adding p24 antigen, mini pool nucl...