scholarly journals Delayed Complex Spike Response Evoked by Conditioned Stimulus Encodes Movement Onset Time and Is Determined by Intrinsic Inferior Olive Properties

2019 ◽  
Vol 13 ◽  
Author(s):  
Yasmin Yarden-Rabinowitz ◽  
Yosef Yarom
Keyword(s):  
Conditioned Stimulus ◽  
Inferior Olive ◽  
Onset Time ◽  
Movement Onset ◽  
Spike Response ◽  
Complex Spike

scholarly journals Modulations of foveal vision associated with microsaccade preparation

2020 ◽  
Vol 117 (20) ◽  
pp. 11178-11183
Author(s):  
Natalya Shelchkova ◽  
Martina Poletti
Keyword(s):  
Eye Movements ◽  
Visual Discrimination ◽  
Target Location ◽  
Onset Time ◽  
Spatial Vision ◽  
Saccade Target ◽  
Foveal Vision ◽  
Movement Onset ◽  
High Acuity ◽  
Gaze Position

It is known that attention shifts prior to a saccade to start processing the saccade target before it lands in the foveola, the high-resolution region of the retina. Yet, once the target is foveated, microsaccades, tiny saccades maintaining the fixated object within the fovea, continue to occur. What is the link between these eye movements and attention? There is growing evidence that these eye movements are associated with covert shifts of attention in the visual periphery, when the attended stimuli are presented far from the center of gaze. Yet, microsaccades are primarily used to explore complex foveal stimuli and to optimize fine spatial vision in the foveola, suggesting that the influences of microsaccades on attention may predominantly impact vision at this scale. To address this question we tracked gaze position with high precision and briefly presented high-acuity stimuli at predefined foveal locations right before microsaccade execution. Our results show that visual discrimination changes prior to microsaccade onset. An enhancement occurs at the microsaccade target location. This modulation is highly selective and it is coupled with a drastic impairment at the opposite foveal location, just a few arcminutes away. This effect is strongest when stimuli are presented closer to the eye movement onset time. These findings reveal that the link between attention and microsaccades is deeper than previously thought, exerting its strongest effects within the foveola. As a result, during fixation, foveal vision is constantly being reshaped both in space and in time with the occurrence of microsaccades.

Nonclock behavior of inferior olive neurons: interspike interval of Purkinje cell complex spike discharge in the awake behaving monkey is random

1995 ◽  
Vol 73 (4) ◽  
pp. 1329-1340 ◽  
Author(s):  
J. G. Keating ◽  
W. T. Thach
Keyword(s):  
Fourier Transform ◽  
Purkinje Cells ◽  
Spike Activity ◽  
Interspike Interval ◽  
Inferior Olive ◽  
Fourier Transforms ◽  
Wrist Movement ◽  
General Role ◽  
Complex Spike ◽  
Bodily Movement

1. Complex spikes of cerebellar Purkinje cells recorded from awake, behaving monkeys were studied to determine the extent to which their discharge could be quantified as periodic. Three Rhesus monkeys were trained to perform up to five different tasks involving rotation of the wrist in relation to a visual cue. Complex spike activity was recorded during task performance and intertrial time. Interspike intervals were determined from the discharge of each of 89 Purkinje cells located throughout lobules IV, V, and VI. Autocorrelation and Fourier transform of the autocorrelation function were performed on the data. In addition, the activity from one cell was transformed so that the discharge occurred on the beat of a 10-Hz clock, and in a further transformation, on the beat of a noisy 10-Hz clock. These transformed data were then analyzed as described above. 2. Fourier transform of the autocorrelogram function of the data that had been transformed to a 10-Hz clock, and that of the noisy 10-Hz clock, both showed a prominent peak at 10 Hz. However, the autocorrelograms and the Fourier transforms of the autocorrelogram functions failed to reveal a prominent periodicity for the actual discharge of any of cells, at any frequency up to 100 Hz: the discharge appeared random with respect to the interspike interval. The discharge was not random with respect to behavior. Complex spike activity was commonly time locked to the start of wrist movement. We examined this discharge to see whether oscillatory discharge could be seen after alignment of the data on the start of wrist movement, or after alignment of the data on the complex spike occurring peri-start of wrist movement. No oscillation was seen for either alignment. 3. The inferior olive, which sends its climbing fibers to the cerebellum, has been implicated in such different activities as 1) pathological tremor of the soft palate, 2) physiological tremor, 3) the normal initiation of all bodily movement, and 4) motor learning. Previous work in pharmacologically or surgically treated animals has shown that, under some conditions, the discharge of these neurons is periodic and synchronous. This firing pattern has been interpreted to support a role in the first two activities. But measurements reported here in the awake monkey show just the opposite: the discharge is aperiodic to the extent of being random. As such, the inferior olive cannot be a "motor clock" in the general role that has been proposed.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals LRP predicts smooth pursuit eye movement onset during the ocular tracking of self-generated movements

2016 ◽  
Vol 116 (1) ◽  
pp. 18-29 ◽  
Author(s):  
Jing Chen ◽  
Matteo Valsecchi ◽  
Karl R. Gegenfurtner
Keyword(s):  
Smooth Pursuit ◽  
Onset Time ◽  
Motor Preparation ◽  
Behavioral Experiment ◽  
Movement Onset ◽  
Ocular Tracking ◽  
Optimal Coordination ◽  
Catch Up ◽  
Finger Motion ◽  
Dot Motion

Several studies have indicated that human observers are very efficient at tracking self-generated hand movements with their gaze, yet it is not clear whether this is simply a by-product of the predictability of self-generated actions or if it results from a deeper coupling of the somatomotor and oculomotor systems. In a first behavioral experiment we compared pursuit performance as observers either followed their own finger or tracked a dot whose motion was externally generated but mimicked their finger motion. We found that even when the dot motion was completely predictable in terms of both onset time and kinematics, pursuit was not identical to that produced as the observers tracked their finger, as evidenced by increased rate of catch-up saccades and by the fact that in the initial phase of the movement gaze was lagging behind the dot, whereas it was ahead of the finger. In a second experiment we recorded EEG in the attempt to find a direct link between the finger motor preparation, indexed by the lateralized readiness potential (LRP) and the latency of smooth pursuit. After taking into account finger movement onset variability, we observed larger LRP amplitudes associated with earlier smooth pursuit onset across trials. The same held across subjects, where average LRP onset correlated with average eye latency. The evidence from both experiments concurs to indicate that a strong coupling exists between the motor systems leading to eye and finger movements and that simple top-down predictive signals are unlikely to support optimal coordination.

Trial-to-Trial Variability of Spike Response of V1 and Saccadic Response Time

2010 ◽  
Vol 104 (5) ◽  
pp. 2556-2572 ◽  
Author(s):  
Jungah Lee ◽  
HyungGoo R. Kim ◽  
Choongkil Lee
Keyword(s):  
Response Time ◽  
Firing Rate ◽  
Spike Activity ◽  
Cell Activity ◽  
Onset Time ◽  
Neural Response ◽  
Target Onset ◽  
Visually Guided ◽  
Spike Response ◽  
Saccadic Response

Single neurons in the primary visual cortex (V1) show variability in spike activity in response to an identical visual stimulus. In the current study, we examined the behavioral significance of the variability in spike activity of V1 neurons for visually guided saccades. We recorded single-cell activity from V1 of monkeys trained to detect and make saccades toward visual targets of varying contrast and analyzed trial-to-trial covariation between the onset time or firing rate of neural response and saccadic response time (RT). Neural latency (NL, the time of the first spike of neural response) was correlated with RT, whereas firing rate (FR) was not. When FR was computed with respect to target onset ignoring NL, a “false” correlation between FR and RT emerged. Multiple regression and partial correlation analyses on NL and FR for predictability of RT variability, as well as a simulation with artificial Poisson spike trains, supported the conclusion that the correlation between FR with respect to target onset and RT was mediated by a correlation between NL and RT, emphasizing the role of trial-to-trial variability of NL for extracting RT-related signals. We attempted to examine laminar differences in RT-related activity. Neurons recorded in the superficial layers tended to show a higher sensitivity to stimulus contrast and a lower correlation with RT compared with those in the lower layers, suggesting a sensory-to-motor transformation within V1 that follows the order of known anatomical connections. These results demonstrate that the trial-to-trial variability of neural response in V1 propagates to the stage of saccade execution, resulting in trial-to-trial variability of RT of a visually guided saccade.

Developmental Changes in Evoked Purkinje Cell Complex Spike Responses

2003 ◽  
Vol 90 (4) ◽  
pp. 2349-2357 ◽  
Author(s):  
Daniel A. Nicholson ◽  
John H. Freeman
Keyword(s):  
Motor Learning ◽  
Purkinje Cell ◽  
Inferior Olive ◽  
Cell Complex ◽  
Climbing Fibers ◽  
Somatosensory Stimulation ◽  
Complex Spike ◽  
Long Latency ◽  
Inhibitory Feedback ◽  
Complex Spikes

The development of synaptic interconnections between the cerebellum and inferior olive, the sole source of climbing fibers, could contribute to the ontogeny of certain forms of motor learning (e.g., eyeblink conditioning). Purkinje cell complex spikes are produced exclusively by climbing fibers and exhibit short- and long-latency activity in response to somatosensory stimulation. Previous studies have demonstrated that evoked short- and long-latency complex spikes generally occur on separate trials and that this response segregation is regulated by inhibitory feedback to the inferior olive. The present experiment tested the hypothesis that complex spikes evoked by periorbital stimulation are regulated by inhibitory feedback from the cerebellum and that this feedback develops between postnatal days (PND) 17 and 24. Recordings from individual Purkinje cell complex spikes in urethan-anesthetized rats indicated that the segregation of short- and long-latency evoked complex spike activity emerges between PND17 and PND24. In addition, infusion of picrotoxin, a GABAA-receptor antagonist, into the inferior olive abolished the response pattern segregation in PND24 rats, producing evoked complex spike response patterns similar to those characteristic of younger rats. These data support the view that cerebellar feedback to the inferior olive, which is exclusively inhibitory, undergoes substantial changes in the same developmental time window in which certain forms of motor learning emerge.

Reproduction of complex spike firing patterns with modulated effective coupling conductance in inferior olive neurons

2010 ◽  
Vol 68 ◽  
pp. e435 ◽  
Author(s):  
Miho Onizuka ◽  
Nicolas Schweighofer ◽  
Yuichi Katori ◽  
Kazuyuki Aihara ◽  
Keisuke Toyama ◽  
...  
Keyword(s):  
Inferior Olive ◽  
Effective Coupling ◽  
Firing Patterns ◽  
Complex Spike ◽  
Inferior Olive Neurons ◽  
Coupling Conductance ◽  
Spike Firing

Effects of Nucleus Prepositus Hypoglossi Lesions on Visual Climbing Fiber Activity in the Rabbit Flocculus

2000 ◽  
Vol 84 (5) ◽  
pp. 2552-2563 ◽  
Author(s):  
M. P. Arts ◽  
C. I. De Zeeuw ◽  
J. Lips ◽  
E. Rosbak ◽  
J. I. Simpson
Keyword(s):  
Constant Velocity ◽  
Inferior Olive ◽  
Vertical Axis ◽  
Firing Frequency ◽  
Optokinetic Stimulation ◽  
Spontaneous Firing ◽  
Complex Spike ◽  
Prepositus Hypoglossi ◽  
Complex Spikes ◽  
Spike Firing

The caudal dorsal cap (dc) of the inferior olive is involved in the control of horizontal compensatory eye movements. It provides those climbing fibers to the vestibulocerebellum that modulate optimally to optokinetic stimulation about the vertical axis. This modulation is mediated at least in part via an excitatory input to the caudal dc from the pretectal nucleus of the optic tract and the dorsal terminal nucleus of the accessory optic system. In addition, the caudal dc receives a substantial GABAergic input from the nucleus prepositus hypoglossi (NPH). To investigate the possible contribution of this bilateral inhibitory projection to the visual responsiveness of caudal dc neurons, we recorded the climbing fiber activity (i.e., complex spikes) of vertical axis Purkinje cells in the flocculus of anesthetized rabbits before and after ablative lesions of the NPH. When the NPH ipsilateral to the recorded flocculus was lesioned, the spontaneous complex spike firing frequency did not change significantly; but when both NPHs were lesioned, the spontaneous complex spike firing frequency increased significantly. When only the contralateral NPH was lesioned, the spontaneous complex spike firing frequency decreased significantly. Neither unilateral nor bilateral lesions had a significant influence on the depth of complex spike modulation during constant velocity optokinetic stimulation or on the transient continuation of complex spike modulation that occurred when the constant velocity optokinetic stimulation stopped. The effects of the lesions on the spontaneous complex spike firing frequency could not be explained when only the projections from the NPH to the inferior olive were considered. Therefore we investigated at the electron microscopic level the nature of the commissural connection between the two NPHs. The terminals of this projection were found to be predominantly GABAergic and to terminate in part on GABAergic neurons. When this inhibitory commissural connection is taken into consideration, then the effects of NPH lesions on the spontaneous firing frequency of floccular complex spikes are qualitatively explicable in terms of relative weighting of the commissural and caudal dc projections of the NPH. In summary, we conclude that in the anesthetized rabbit the inhibitory projection of the NPH to the caudal dc influences the spontaneous firing frequency of floccular complex spikes but not their modulation by optokinetic stimulation.

scholarly journals Neurons of the inferior olive respond to broad classes of sensory input while subject to homeostatic control

2018 ◽  
Author(s):  
Chiheng Ju ◽  
Laurens W.J. Bosman ◽  
Tycho M. Hoogland ◽  
Arthiha Velauthapillai ◽  
Pavithra Murugesan ◽  
...  
Keyword(s):  
Purkinje Cells ◽  
Inferior Olive ◽  
Recent History ◽  
Climbing Fibre ◽  
Homeostatic Control ◽  
Complex Spike ◽  
History Of ◽  
Sensory Evoked ◽  
Complex Spikes ◽  
Spike Firing

AbstractCerebellar Purkinje cells integrate sensory information with motor efference copies to adapt movements to behavioural and environmental requirements. They produce complex spikes that are triggered by the activity of climbing fibres originating in neurons of the inferior olive. These complex spikes can shape the onset, amplitude and direction of movements as well as the adaptation of such movements to sensory feedback. Clusters of nearby inferior olive neurons project to parasagittally aligned stripes of Purkinje cells, referred to as “microzones”. It is currently unclear to what extent individual Purkinje cells within a single microzone integrate climbing fibre inputs from multiple sources of different sensory origins, and to what extent sensory-evoked climbing fibre responses depend on the strength and recent history of activation. Here we imaged complex spike responses in cerebellar lobule crus 1 to various types of sensory stimulation in awake mice. We find that different sensory modalities and receptive fields have a mild, but consistent, tendency to converge on individual Purkinje cells. Purkinje cells encoding the same stimulus show increased events with coherent complex spike firing and tend to lie close together. Moreover, whereas complex spike firing is only mildly affected by variations in stimulus strength, it strongly depends on the recent history of climbing fibre activity. Our data point towards a mechanism in the olivo-cerebellar system that regulates complex spike firing during mono- or multisensory stimulation around a relatively low set-point, highlighting an integrative coding scheme of complex spike firing under homeostatic control.

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