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Changes in simple spike activity during saccade adaptation
S170
Abstracts
We investigated the spatial distribution of simple-spike response types of Purkinje cells (P-cells) within the cerebellar nodulus and uvula during sinusoidal head rotation in vertical plane in awake cats. Cells demonstrating the strongest response to the roll plane tended to be located in a parasagittal band extending more than 1.0 mm lateral to the midline, while those with the strongest response to pitch plane tended to be located in a band extending up to 1.0 mm from the midline. These findings suggest that there are at least 2 sagittal functional zones with a rostrocaudal extent in the search area examined in the present study. Such spatial information might be transmitted to the brainstem nuclei to control motor dynamics for the optokinetic responses under head-tilt conditions in each specific plane.
P2-g22 Changes in simple spike activity during saccade adaptation Yoshiko Kojima, Robijanto Soetedjo, Albert F. Fuchs Department of Physiology and Biophysics, WaNPRC, University of Washington, Japan The oculomotor system adjusts saccade size to reduce the error produced by persistent dysmetrias. During amplitude decrease adaptation, the activity of neurons in the cerebellar caudal fastigial nucleus (cFN) decreases with contraversive and increases with ipsiversive saccades. The cFN receives inhibitory projections from Purkinje (P-cells) in the oculomotor vermis. Here we tested how the simple spike (SS) activity of P-cells changed during adaptation.Complex spikes (CS) discharge best when an inaccurate saccade causes an error in a preferred (on) direction. If CSs report an error signal that drives saccade adaptation, SS activity also should change with adaptation in that direction. Therefore, after determining a unit’s CS-on direction, we adapted saccades in that and the opposite (off) direction.During adaptation, SS activity of 14/36 P-cells decreased in the CS-on direction. Ten showed an increase in the CS-off direction. Twelve showed no change.These changes are appropriate to influence cFN neurons in ways that could help produce adaptation. doi:10.1016/j.neures.2009.09.889
P2-g25 Supplementary eye fields (SEF) and memory-based smooth pursuit eye movements: Working memory and decision processes Natsuko Shichinohe 1,2 , Teppei Akao 1 , Sergei Kurkin 1 , Junko Fukushima 3 , Chris R.S. Kaneko 4 , Kikuro Fukushima 1 Dept Physiol, Hokkaido Univ Sch Med, Japan; 2 Dept Ophthalmol, Hokkaido Univ Sch Med, Japan; 3 Dept Health Sciences, Hokkaido Univ Sch Med, Japan; 4 Dept Physiol & Biophysics & Washington National Primate Res Center, Univ Washington, USA Accurate smooth pursuit requires prediction to compensate for delays in processing target motion and/or generating eye velocity commands. In previous studies, prediction-related discharge reported in SEF did not distinguish discharge related to preparation for pursuit from discharge related to processing visual motion signals. A memory-based smooth pursuit task designed to distinguish the two components showed SEF contained signals coding memory of visual motion-direction, the decision of whether or not to pursue, and the preparation for pursuit. Bilateral muscimol injection into SEF resulted in direction errors, errors of whether or not to pursue, and reduction of initial pursuit eye velocity. Our results show the SEF plays a role in working memory for, and the decision processes leading to pursuit eye movements. doi:10.1016/j.neures.2009.09.892
P2-g26 Otolith inputs to pursuit neurons in the caudal part of the frontal eye fields (FEF) in monkeys Teppei Akao, Sergei Kurkin, Junko Fukushima, Kikuro Fukushima Dept of Physiology, Hokkaido University School of Medicine, Sapporo, Japan
P2-g23 Changes in saccade metrics associated with adaptation elicited by electrical stimulation of the superior colliculus Yuki Kaku 1,2 , Kaoru Yoshida 2 , Yoshiki Iwamoto 2 Uekusa Gakuen University, Chiba, Japan; Tsukuba, Tsukuba, Japan
doi:10.1016/j.neures.2009.09.891
1
doi:10.1016/j.neures.2009.09.888
1
area (LIP) of the ipsilesional side and not found in those areas of the contralesional side. Our results suggested that MT and LIP are involved in the control of saccades after V1 lesion.
2
Dept Neurophysiol, Univ of
We have recently reported that repetitive pairing of saccades with electrical stimulation of the deeper layers of the superior colliculus (SC) could elicit saccade adaptation. Here we analyzed how saccade metrics might change during the course of the SC-induced adaptation. Two juvenile rhesus monkeys were trained to make saccades to a visual target that jumped along the horizontal meridian. The SC was stimulated ∼50 ms after the end of saccades in one horizontal direction. The stimulus intensity was below the threshold for evoking saccades. Increases in radial amplitude of stimulation-paired saccades were accompanied by increases in peak radial velocity. Similarly, decreases in radial amplitude were accompanied by decreases in peak radial velocity. The course of the radial amplitude changes was similar to that of the peak velocity changes. These results suggest that the SC stimulationinduced “adaptive” change in saccade amplitude results primarily from changes in peak saccade velocity. doi:10.1016/j.neures.2009.09.890
P2-g24 Activation study by positron emission tomography for visually guided saccade in the monkey with lesion of the primary visual cortex Rikako Kato 1,2 , Takuro Ikeda 1,2 , Hirotaka Onoe 3 , Masayuki Kawahara 4 , Masatoshi Yoshida 1,5 , Kana Takaura 1,5 , Hideo Tsukada 4 , Tadashi Isa 1,2,5 1
Department Dev. Physiol., Nat’l Inst. Physiol. Sci., Okazaki; 2 CREST, JST, Kawaguchi, Japan; 3 Function. Probe Res. Lab., CMIS, RIKEN, Kobe, Japan; 4 Central Res. Lab., Hamamatsu Photonics, Hamamatsu, Japan; 5 Sch. Life Sci., Grad. University Adv. Stud., Hayama, Japan Some patients with damage to the primary visual cortex (V1) retain the ability to localize visual stimuli in their affected visual field by the eye movement or hand reaching. This ability should dependent upon the remaining pathway in the visuomotor system. Our monkey with unilateral V1 lesion also can make saccades to stimuli in the affected field. We examined activation areas related to those saccades by positron emission tomography (PET). Activations correlated with the number of saccades were found in the middle temporal area (MT) and the lateral intraparietal
The smooth-pursuit system must interact with the vestibular system to maintain the accuracy of eye movements in space not only during head rotation which activates primarily semi-circular canals but also during head translation which activates otolith organs. The majority of pursuit neurons in the FEF receive vestibular inputs induced by whole body rotation. However, it has not been tested whether FEF pursuit neurons receive otolith inputs. In the present study, we tested discharge modulation of FEF pursuit neurons during fore/aft and/or right/left translation by passively moving the whole body sinusoidally at 0.33 Hz (±10 cm). The majority of FEF pursuit neurons were activated by translation even without a target in complete darkness. There was no correlation between the magnitude of discharge modulation and translational vestibulo-ocular reflex (VOR). Preferred directions of translational responses were distributed nearly evenly in front of the monkeys. These results indicate that FEF pursuit neurons receive otolith inputs. doi:10.1016/j.neures.2009.09.893
P2-g27 Analysis of Floccular Purkinje (P-) Cell Discharge during 3D Pursuit Sergei Kurkin, Takashi Tsubuku, Teppei Akao, Junko Fukushima, Kikuro Fukushima Dept Physiol, Hokkaido University, Sapporo, Japan Floccular P-cells code eye motion during smooth pursuit. We analyzed 3D directional and position/velocity sensitivity of P-cells during sinusoidal and ramp spot motion in 3D space by fitting spike discharge with time-shifted linear combination of position and velocity components. Of 109 P-cells tested, 75% responded to both frontal and vergence pursuit, 17% to frontal pursuit only, and 8% to vergence only. Position-velocity sensitivity was estimated by (1) averaged Pearson correlation coefficients calculated separately for position and velocity, (2) slopes of best-fit simple regression lines and (3) multiple regression coefficients. All 3 methods showed consistent position/velocity sensitivity ratios (PVSR): significant position preference in vergence pursuit (PVSR = 1.42), higher sensitivity to velocity in horizontal rpursuit (PVSR = 0.73) and no position-velocity preference in vertical pursuit (PVSR = 1.02). Position and velocity preferred directions were the same in the majority of P-cells tested. Our results indicate different PVSR for different preferred directions. doi:10.1016/j.neures.2009.09.894
Abstracts
We investigated the spatial distribution of simple-spike response types of Purkinje cells (P-cells) within the cerebellar nodulus and uvula during sinusoidal head rotation in vertical plane in awake cats. Cells demonstrating the strongest response to the roll plane tended to be located in a parasagittal band extending more than 1.0 mm lateral to the midline, while those with the strongest response to pitch plane tended to be located in a band extending up to 1.0 mm from the midline. These findings suggest that there are at least 2 sagittal functional zones with a rostrocaudal extent in the search area examined in the present study. Such spatial information might be transmitted to the brainstem nuclei to control motor dynamics for the optokinetic responses under head-tilt conditions in each specific plane.
P2-g22 Changes in simple spike activity during saccade adaptation Yoshiko Kojima, Robijanto Soetedjo, Albert F. Fuchs Department of Physiology and Biophysics, WaNPRC, University of Washington, Japan The oculomotor system adjusts saccade size to reduce the error produced by persistent dysmetrias. During amplitude decrease adaptation, the activity of neurons in the cerebellar caudal fastigial nucleus (cFN) decreases with contraversive and increases with ipsiversive saccades. The cFN receives inhibitory projections from Purkinje (P-cells) in the oculomotor vermis. Here we tested how the simple spike (SS) activity of P-cells changed during adaptation.Complex spikes (CS) discharge best when an inaccurate saccade causes an error in a preferred (on) direction. If CSs report an error signal that drives saccade adaptation, SS activity also should change with adaptation in that direction. Therefore, after determining a unit’s CS-on direction, we adapted saccades in that and the opposite (off) direction.During adaptation, SS activity of 14/36 P-cells decreased in the CS-on direction. Ten showed an increase in the CS-off direction. Twelve showed no change.These changes are appropriate to influence cFN neurons in ways that could help produce adaptation. doi:10.1016/j.neures.2009.09.889
P2-g25 Supplementary eye fields (SEF) and memory-based smooth pursuit eye movements: Working memory and decision processes Natsuko Shichinohe 1,2 , Teppei Akao 1 , Sergei Kurkin 1 , Junko Fukushima 3 , Chris R.S. Kaneko 4 , Kikuro Fukushima 1 Dept Physiol, Hokkaido Univ Sch Med, Japan; 2 Dept Ophthalmol, Hokkaido Univ Sch Med, Japan; 3 Dept Health Sciences, Hokkaido Univ Sch Med, Japan; 4 Dept Physiol & Biophysics & Washington National Primate Res Center, Univ Washington, USA Accurate smooth pursuit requires prediction to compensate for delays in processing target motion and/or generating eye velocity commands. In previous studies, prediction-related discharge reported in SEF did not distinguish discharge related to preparation for pursuit from discharge related to processing visual motion signals. A memory-based smooth pursuit task designed to distinguish the two components showed SEF contained signals coding memory of visual motion-direction, the decision of whether or not to pursue, and the preparation for pursuit. Bilateral muscimol injection into SEF resulted in direction errors, errors of whether or not to pursue, and reduction of initial pursuit eye velocity. Our results show the SEF plays a role in working memory for, and the decision processes leading to pursuit eye movements. doi:10.1016/j.neures.2009.09.892
P2-g26 Otolith inputs to pursuit neurons in the caudal part of the frontal eye fields (FEF) in monkeys Teppei Akao, Sergei Kurkin, Junko Fukushima, Kikuro Fukushima Dept of Physiology, Hokkaido University School of Medicine, Sapporo, Japan
P2-g23 Changes in saccade metrics associated with adaptation elicited by electrical stimulation of the superior colliculus Yuki Kaku 1,2 , Kaoru Yoshida 2 , Yoshiki Iwamoto 2 Uekusa Gakuen University, Chiba, Japan; Tsukuba, Tsukuba, Japan
doi:10.1016/j.neures.2009.09.891
1
doi:10.1016/j.neures.2009.09.888
1
area (LIP) of the ipsilesional side and not found in those areas of the contralesional side. Our results suggested that MT and LIP are involved in the control of saccades after V1 lesion.
2
Dept Neurophysiol, Univ of
We have recently reported that repetitive pairing of saccades with electrical stimulation of the deeper layers of the superior colliculus (SC) could elicit saccade adaptation. Here we analyzed how saccade metrics might change during the course of the SC-induced adaptation. Two juvenile rhesus monkeys were trained to make saccades to a visual target that jumped along the horizontal meridian. The SC was stimulated ∼50 ms after the end of saccades in one horizontal direction. The stimulus intensity was below the threshold for evoking saccades. Increases in radial amplitude of stimulation-paired saccades were accompanied by increases in peak radial velocity. Similarly, decreases in radial amplitude were accompanied by decreases in peak radial velocity. The course of the radial amplitude changes was similar to that of the peak velocity changes. These results suggest that the SC stimulationinduced “adaptive” change in saccade amplitude results primarily from changes in peak saccade velocity. doi:10.1016/j.neures.2009.09.890
P2-g24 Activation study by positron emission tomography for visually guided saccade in the monkey with lesion of the primary visual cortex Rikako Kato 1,2 , Takuro Ikeda 1,2 , Hirotaka Onoe 3 , Masayuki Kawahara 4 , Masatoshi Yoshida 1,5 , Kana Takaura 1,5 , Hideo Tsukada 4 , Tadashi Isa 1,2,5 1
Department Dev. Physiol., Nat’l Inst. Physiol. Sci., Okazaki; 2 CREST, JST, Kawaguchi, Japan; 3 Function. Probe Res. Lab., CMIS, RIKEN, Kobe, Japan; 4 Central Res. Lab., Hamamatsu Photonics, Hamamatsu, Japan; 5 Sch. Life Sci., Grad. University Adv. Stud., Hayama, Japan Some patients with damage to the primary visual cortex (V1) retain the ability to localize visual stimuli in their affected visual field by the eye movement or hand reaching. This ability should dependent upon the remaining pathway in the visuomotor system. Our monkey with unilateral V1 lesion also can make saccades to stimuli in the affected field. We examined activation areas related to those saccades by positron emission tomography (PET). Activations correlated with the number of saccades were found in the middle temporal area (MT) and the lateral intraparietal
The smooth-pursuit system must interact with the vestibular system to maintain the accuracy of eye movements in space not only during head rotation which activates primarily semi-circular canals but also during head translation which activates otolith organs. The majority of pursuit neurons in the FEF receive vestibular inputs induced by whole body rotation. However, it has not been tested whether FEF pursuit neurons receive otolith inputs. In the present study, we tested discharge modulation of FEF pursuit neurons during fore/aft and/or right/left translation by passively moving the whole body sinusoidally at 0.33 Hz (±10 cm). The majority of FEF pursuit neurons were activated by translation even without a target in complete darkness. There was no correlation between the magnitude of discharge modulation and translational vestibulo-ocular reflex (VOR). Preferred directions of translational responses were distributed nearly evenly in front of the monkeys. These results indicate that FEF pursuit neurons receive otolith inputs. doi:10.1016/j.neures.2009.09.893
P2-g27 Analysis of Floccular Purkinje (P-) Cell Discharge during 3D Pursuit Sergei Kurkin, Takashi Tsubuku, Teppei Akao, Junko Fukushima, Kikuro Fukushima Dept Physiol, Hokkaido University, Sapporo, Japan Floccular P-cells code eye motion during smooth pursuit. We analyzed 3D directional and position/velocity sensitivity of P-cells during sinusoidal and ramp spot motion in 3D space by fitting spike discharge with time-shifted linear combination of position and velocity components. Of 109 P-cells tested, 75% responded to both frontal and vergence pursuit, 17% to frontal pursuit only, and 8% to vergence only. Position-velocity sensitivity was estimated by (1) averaged Pearson correlation coefficients calculated separately for position and velocity, (2) slopes of best-fit simple regression lines and (3) multiple regression coefficients. All 3 methods showed consistent position/velocity sensitivity ratios (PVSR): significant position preference in vergence pursuit (PVSR = 1.42), higher sensitivity to velocity in horizontal rpursuit (PVSR = 0.73) and no position-velocity preference in vertical pursuit (PVSR = 1.02). Position and velocity preferred directions were the same in the majority of P-cells tested. Our results indicate different PVSR for different preferred directions. doi:10.1016/j.neures.2009.09.894