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.

scholarly journals Effects of Processing Difficulty on Eye Movements in Reading: A Review of Behavioral and Neural Observations

2012 ◽  
Vol 5 (4) ◽  
Author(s):  
Shun-nan Yang
Keyword(s):  
Eye Movements ◽  
Electric Current ◽  
Present Article ◽  
Onset Time ◽  
Target Onset ◽  
Visually Guided ◽  
Applied Current ◽  
Effect Theory ◽  
Reading Text ◽  
Processing Difficulty

In reading, text difficulties increase the duration of eye fixation and the frequency of refixation and regression. The present article reviews previous attempts to quantify these effects based on the frequency of effect theory (FET), and links these effects to results from microstimulation of primate supple-mentary eye fields. Observed stimulation effects on the latency and frequency of visually-guided saccades depend on the onset time of electric current relative to target onset, and the strength of applied current. Resultant saccade delay was only observed for those made towards a highly predictive location ipsilateral to stimulated SEF sites. These findings are inter-preted in the context of reading, where the detection of processing difficulty allows a suppression signal to supersede a forward saccade signal in a time race. This in turn permits a cognitively-based refixation/regression to be initiated in place of the suppressed forward saccade.

scholarly journals Potentiation of cerebellar Purkinje cells facilitates whisker reflex adaptation through increased simple spike activity

2018 ◽  
Author(s):  
Vincenzo Romano ◽  
Licia De Propris ◽  
Laurens W.J. Bosman ◽  
Pascal Warnaar ◽  
Michiel M. ten Brinke ◽  
...  
Keyword(s):  
Purkinje Cell ◽  
Purkinje Cells ◽  
Spike Activity ◽  
Cell Activity ◽  
Response Probability ◽  
Long Term Potentiation ◽  
Parallel Fiber ◽  
Spike Response ◽  
Simple Spike ◽  
Cerebellar Plasticity

SummaryCerebellar plasticity underlies motor learning. However, how the cerebellum operates to enable learned changes in motor output is largely unknown. We developed a sensory-driven adaptation protocol for reflexive whisker protraction and recorded Purkinje cell activity from crus 1 and 2 of awake mice. Before training, simple spikes of individual Purkinje cells correlated during reflexive protraction with the whisker position without lead or lag. After training, simple spikes and whisker protractions were both enhanced with the spiking activity now leading the behavioral response. Neuronal and behavior changes did not occur in two cell-specific mouse models with impaired long-term potentiation at parallel fiber to Purkinje cell synapses. Consistent with cerebellar plasticity rules, increased simple spike activity was prominent in cells with low complex spike response probability. Thus, potentiation at parallel fiber to Purkinje cell synapses may contribute to reflex adaptation and enable expression of cerebellar learning through increases in simple spike activity.Impact statementRomano et al. show that expression of cerebellar whisker learning can be mediated by increases in simple spike activity, depending on LTP induction at parallel fiber to Purkinje cell synapses.

scholarly journals Potentiation of cerebellar Purkinje cells facilitates whisker reflex adaptation through increased simple spike activity

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Vincenzo Romano ◽  
Licia De Propris ◽  
Laurens WJ Bosman ◽  
Pascal Warnaar ◽  
Michiel M ten Brinke ◽  
...  
Keyword(s):  
Purkinje Cell ◽  
Purkinje Cells ◽  
Spike Activity ◽  
Cell Activity ◽  
Response Probability ◽  
Long Term Potentiation ◽  
Parallel Fiber ◽  
Spike Response ◽  
Simple Spike ◽  
Cerebellar Plasticity

Cerebellar plasticity underlies motor learning. However, how the cerebellum operates to enable learned changes in motor output is largely unknown. We developed a sensory-driven adaptation protocol for reflexive whisker protraction and recorded Purkinje cell activity from crus 1 and 2 of awake mice. Before training, simple spikes of individual Purkinje cells correlated during reflexive protraction with the whisker position without lead or lag. After training, simple spikes and whisker protractions were both enhanced with the spiking activity now leading behavioral responses. Neuronal and behavioral changes did not occur in two cell-specific mouse models with impaired long-term potentiation at their parallel fiber to Purkinje cell synapses. Consistent with cerebellar plasticity rules, increased simple spike activity was prominent in cells with low complex spike response probability. Thus, potentiation at parallel fiber to Purkinje cell synapses may contribute to reflex adaptation and enable expression of cerebellar learning through increases in simple spike activity.

Express Saccades and Smooth Pursuit Eye Movement Function in Schizophrenic, Affective Disorder, and Normal Subjects

1993 ◽  
Vol 5 (3) ◽  
pp. 303-316 ◽  
Author(s):  
Anne B. Sereno ◽  
Philip S. Holzman
Keyword(s):  
Response Time ◽  
Eye Movement ◽  
Smooth Pursuit ◽  
Normal Subjects ◽  
Control Group ◽  
Saccadic Response ◽  
Group A ◽  
Schizophrenic Group ◽  
Movement Function ◽  
Normal Controls

Saccadic and smooth pursuit eye movements were recorded in three groups of subjects: a schizophrenic group, a non-schizophrenic psychotic patient comparison group, and a normal control group. Schizophrenic subjects demonstrated a greater decrease in saccadic response time than did normal controls in a gap task (when the fixation point was turned off 150 msec before the target appeared). The psychiatric comparison subjects did not differ from normal controls. Further, only schizophrenic subjects demonstrated a relation between smooth pursuit and saccadic eye movement performance, such that subjects with impaired smooth pursuit showed a larger decrease in saccadic response time in the gap task. The relation between performance on the gap task and quality of smooth pursuit and its relevance for a prefrontal deficit hypothesis of schizophrenia are discussed.

scholarly journals Position-theta-phase model of hippocampal place cell activity applied to quantification of running speed modulation of firing rate

2019 ◽  
Author(s):  
Kathryn McClain ◽  
David Tingley ◽  
David Heeger ◽  
György Buzsáki
Keyword(s):  
Firing Rate ◽  
Spatial Information ◽  
Cell Activity ◽  
Gain Control ◽  
Place Cell ◽  
Small Subset ◽  
Running Speed ◽  
Speed Modulation ◽  
Place Fields ◽  
Theta Phase

AbstractSpiking activity of place cells in the hippocampus encodes the animal’s position as it moves through an environment. Within a cell’s place field, both the firing rate and the phase of spiking in the local theta oscillation contain spatial information. We propose a position-theta-phase (PTP) model that captures the simultaneous expression of the firing-rate code and theta-phase code in place cell spiking. This model parametrically characterizes place fields to compare across cells, time and condition, generates realistic place cell simulation data, and conceptualizes a framework for principled hypothesis testing to identify additional features of place cell activity. We use the PTP model to assess the effect of running speed in place cell data recorded from rats running on linear tracks. For the majority of place fields we do not find evidence for speed modulation of the firing rate. For a small subset of place fields, we find firing rates significantly increase or decrease with speed. We use the PTP model to compare candidate mechanisms of speed modulation in significantly modulated fields, and determine that speed acts as a gain control on the magnitude of firing rate. Our model provides a tool that connects rigorous analysis with a computational framework for understanding place cell activity.SignificanceThe hippocampus is heavily studied in the context of spatial navigation, and the format of spatial information in hippocampus is multifaceted and complex. Furthermore, the hippocampus is also thought to contain information about other important aspects of behavior such as running speed, though there is not agreement on the nature and magnitude of their effect. To understand how all of these variables are simultaneously represented and used to guide behavior, a theoretical framework is needed that can be directly applied to the data we record. We present a model that captures well-established spatial-encoding features of hippocampal activity and provides the opportunity to identify and incorporate novel features for our collective understanding.

Cerebellar Flocculus and Paraflocculus Purkinje Cell Activity During Circular Pursuit in Monkey

2000 ◽  
Vol 83 (1) ◽  
pp. 13-30 ◽  
Author(s):  
H.-C. Leung ◽  
M. Suh ◽  
R. E. Kettner
Keyword(s):  
Purkinje Cell ◽  
Firing Rate ◽  
Smooth Pursuit ◽  
Cell Activity ◽  
Two Dimensional ◽  
Rotation Direction ◽  
Cell Responses ◽  
Preferred Direction ◽  
Velocity Sensitivity ◽  
Multilinear Function

Responses from 69 Purkinje cells in the flocculus and paraflocculus of two rhesus monkeys were studied during smooth pursuit of targets moving along circular trajectories and compared with responses during sinusoidal pursuit and fixation. A variety of interesting responses was observed during circular pursuit. Although some neurons fired most strongly in a single preferred direction during clockwise (CW) and counterclockwise (CCW) pursuit, others had directional preferences that changed with rotation direction. Some of these neurons showed similar modulation amplitudes during CW and CCW pursuit, whereas other neurons showed a preference for a particular rotation direction. Response specificity also was observed during sinusoidal pursuit. Some neurons showed responses that were much stronger during centrifugal pursuit, others showed a preference for centripetal pursuit, and still others showed responses during both centripetal and centrifugal motion. Differences in preferred response direction were sometimes observed for centripetal versus centrifugal pursuit. CW/CCW and centrifugal/centripetal preferences were not explained by a breakdown in component additivity. That is, modulations in firing rate during pursuit along a circular trajectory equaled the sum of modulations during horizontal and vertical sinusoidal components as well as for diagonal components. Instead all responses were well fit by a model that expressed the instantaneous firing rate of each neuron as a multilinear function of the two-dimensional position and velocity of the eye. This model generalized well to performance at different sinusoidal frequencies. It did somewhat less well for responses during fixation, suggesting some separation in the neural mechanisms of dynamic and static positioning. The model indicates that position sensitivity accounted for ∼36% of the modulation during circular pursuit, and velocity sensitivity accounted for ∼64%. When position and velocity sensitivity vectors were aligned, responses were simpler and modulations were similar during CW versus CCW pursuit. In contrast, when these vectors pointed in different directions, response complexity increased. Nonaligned position and velocity influences tended to reinforce during circular pursuit in one direction and to cancel each other during pursuit in the opposite direction. They also tended to produce response differences during centripetal versus centrifugal sinusoidal pursuit. The distinct roles played by position and velocity in shaping Purkinje cell responses are compatible with the control signals required to generate smooth pursuit along circular and other two-dimensional trajectories.

Neural representations of the target (goal) of visually guided arm movements in three motor areas of the monkey

1990 ◽  
Vol 64 (1) ◽  
pp. 164-178 ◽  
Author(s):  
G. E. Alexander ◽  
M. D. Crutcher
Keyword(s):  
Primary Motor Cortex ◽  
Cell Activity ◽  
Motor Area ◽  
Visually Guided ◽  
Spatial Features ◽  
Tracking Tasks ◽  
Neural Representations ◽  
Preparatory Activity ◽  
Standard Task ◽  
The Right

1. This study was designed to determine whether the supplementary motor area (SMA), the primary motor cortex (MC), and the putamen, all of which are components of the basal ganglia-thalamocortical “motor circuit,” contain neural representations of the target or goal of a movement, independent of specific features of the movement itself. Four rhesus monkeys were trained to perform two visuomotor delayed step-tracking tasks in which the subject used a cursor to track targets on a display screen by making flexion and extension movements of the elbow. Single-cell activity was recorded from the SMA, MC, and putamen while the monkeys performed the two tasks. In the Standard task, the cursor and the forearm moved in the same direction. The Cursor/Limb Inversion task was identical to the Standard task except that there was an inverse relationship between the directions of movement of the forearm and cursor. Together, these tasks dissociated the spatial features of the target or goal of the movement from those of the movement itself. Both tasks also included features that made it possible to distinguish neuronal activity related to the preparation for movement from that related to movement execution. A total of 554 directionally selective, task-related neurons were tested with both tasks (SMA, 207; MC, 198; putamen, 149). 2. Two types of directionally selective preparatory activity were seen in each motor area. Cells with target-dependent preparatory activity showed selective discharge prior to all preplanned movements of the cursor toward one of the side targets (right or left), irrespective of whether the limb movement involved extension or flexion of the elbow. Comparable proportions of target-dependent preparatory cells were seen in the SMA (36%), MC (40%), and putamen (38%). Cells with limb-dependent preparatory activity showed selective discharge prior to all preplanned elbow movements in a particular direction (extension or flexion), irrespective of whether the target to which the cursor was moved was located on the right or left side of the display. The SMA contained a higher proportion of limb-dependent preparatory cells (40%) than either MC (15%) or putamen (9%). 3. Two types of directionally selective movement-related activity were also seen in each motor area.(ABSTRACT TRUNCATED AT 400 WORDS)

Multiple, prolonged actions of neuroendocrine bag cells on neurons in Aplysia. I. Effects on bursting pacemaker neurons

1979 ◽  
Vol 42 (4) ◽  
pp. 1165-1184 ◽  
Author(s):  
E. Mayeri ◽  
P. Brownell ◽  
W. D. Branton ◽  
S. B. Simon
Keyword(s):  
Spike Activity ◽  
Ganglion Cells ◽  
Cell Activity ◽  
Egg Laying ◽  
Neuroendocrine Cells ◽  
Abdominal Ganglion ◽  
Normal Expression ◽  
The Central Nervous System ◽  
Bag Cells ◽  
Local Stimulation

1. The bag cells are a group of neuroendocrine cells located in the abdominal ganglion of Aplysia. Accumulated evidence suggests they synthesize and release egg-laying hormone (ELH), a peptide that induces egg laying. In this and the following paper (37) we describe five types of prolonged neural responses in cells of the isolated abdominal ganglion that are produced by stimulated bag cell activity. 2. Prolonged, 5- to 40-min bursts of spike activity were triggered in the normally silent bag cells by local stimulation of one of the bag cell clusters with brief, 0.6- to 2-strains of pulses. This local stimulation minimized the possible effects of the stimulus on other ganglion cells and initiated bag cell activity similar to what has been recorded in intact animals at the initiation of egg laying. 3. Following onset of triggered bag cell activity there is an increase in the amplitude of the bursting pacemaker potential in cell R15 that results in augmented bursting activity in this autoactive cell for up to 3 h. The increase begins in less than 1 min and reaches a maximim after 8--20 min. In two other bursting pacemaker cells, L3 and L6, there is a second type of response, slow inhibition, consisting of a smoothly graded hyperpolarization that begins in 5--14 s, reaches a peak value of 10--20 mV after 30 s, and results in a decrease in the spontaneous spike activity of these cells for 3 h or longer. Both types of responses are contingent on the occurrence of bag cell activity, they depend on prolonged bag cell activity for their normal expression, and they occur in the absence of the fast interactions characteristic of conventional synapses. 4. The results reveal at the level of intracellular recordings prolonged actions of peptide-secreting neuroendocrine cells on the central nervous system. The role of ELH as a putative mediator of one or more of these actions is discussed.

Contrasting properties of monkey somatosensory and motor cortex neurons activated during the control of force in precision grip

1991 ◽  
Vol 65 (3) ◽  
pp. 572-589 ◽  
Author(s):  
T. M. Wannier ◽  
M. A. Maier ◽  
M. C. Hepp-Reymond
Keyword(s):  
Firing Rate ◽  
Neuronal Activity ◽  
Isometric Force ◽  
Precision Grip ◽  
Cell Activity ◽  
Emg Activity ◽  
Firing Patterns ◽  
Neuronal Populations ◽  
Force Increase ◽  
Discharge Patterns

1. Single cell activity was investigated in the precentral motor (MI) and postcentral somatosensory (SI) cortex of the monkey to compare the neuronal activity related to the control of isometric force in the precision grip and to assess the participation of SI in motor control. 2. Three monkeys (Macaca fascicularis) were trained in a visual step-tracking paradigm to generate and precisely maintain force on a transducer held between thumb and index finger. Great care was taken to have the monkeys use only their fingers without moving the wrist or proximal joints. In two monkeys electromyographic (EMG) activity was checked in 23 muscles over several sessions. 3. Five similar classes of task-related firing patterns were found in both SI and MI cortical hand and finger representations, but their relative proportions differed. The majority of the SI neurons were phasically or phasic-tonically active (61%), whereas in MI the neurons that decreased their firing rate with force were most frequent (42%). 4. The timing of activity changes related to the onset of force increase from low to higher levels strongly differed in the two neuronal populations. In SI, only 14% of the task-related neurons increased or decreased their firing rate before the onset of force increase, in contrast to 56% in MI. Only 3% of the SI neurons showed changes before the earliest EMG activation. 5. In both SI and MI neurons with tonic and phasic-tonic, increasing or decreasing discharge patterns disclosed a relationship between neuronal activity and static force. Distinction was made between neurons modulating their activity in a monotonic way and those that were active only at one force level and had a kind of recruitment or deactivation threshold. The latter ones were more frequent in MI than in SI, and in the neuron population with decreasing firing patterns. For the neurons with increases in activity, statistically significant linear correlations between firing rate and force were found more frequently in MI than in SI, where the proportion of nonsignificant correlations was relatively high (35% vs. 15% in MI). In SI the indexes of force sensitivity, calculated from the slopes of the regression lines, covered a wider range than in MI; and their distribution was bimodal, with one mean of 30 Hz/N and the other of 155 Hz/N. In contrast, the mean rate-force slope in MI was 69 Hz/N.(ABSTRACT TRUNCATED AT 400 WORDS)

Activation of Metabotropic Glutamate 2/3 Receptors Reverses the Effects of NMDA Receptor Hypofunction on Prefrontal Cortex Unit Activity in Awake Rats

2005 ◽  
Vol 93 (4) ◽  
pp. 1989-2001 ◽  
Author(s):  
Houman Homayoun ◽  
Mark E. Jackson ◽  
Bita Moghaddam
Keyword(s):  
Prefrontal Cortex ◽  
Nmda Receptor ◽  
Firing Rate ◽  
Spike Activity ◽  
Systemic Exposure ◽  
Nmda Antagonist ◽  
Laboratory Animals ◽  
Cellular Mechanisms ◽  
Physiological Basis ◽  
Metabotropic Glutamate

Systemic exposure to N-methyl-d-aspartate (NMDA) receptor antagonists can lead to psychosis and prefrontal cortex (PFC)–dependent behavioral impairments. Agonists of metabotropic glutamate 2/3 (mGlu2/3) receptors ameliorate the adverse behavioral effects of NMDA antagonists in humans and laboratory animals, and are being considered as a novel treatment for some symptoms of schizophrenia. Despite the compelling behavioral data, the cellular mechanisms by which potentiation of mGlu2/3 receptor function attenuates the effects of NMDA receptor hypofunction remain unclear. In freely moving rats, we recorded the response of medial PFC (prelimbic) single units to treatment with the NMDA antagonist MK801 and assessed the dose-dependent effects of pre- or posttreatment with the mGlu2/3 receptor agonist LY354740 on this response. NMDA receptor antagonist-induced behavioral stereotypy was measured during recording because it may relate to the psychotomimetic properties of this treatment and is dependent on the functional integrity of the PFC. In most PFC neurons, systemic administration of MK801 increased the spontaneous firing rate, decreased the variability of spike trains, and disrupted patterns of spontaneous bursts. Given alone, LY354740 (1, 3, and 10 mg/kg) decreased spontaneous activity of PFC neurons at the highest dose. Pre- or posttreatment with LY354740 blocked MK801-induced changes on firing rate, burst activity, and variability of spike activity. These physiological changes coincided with a reduction in MK801-induced behavioral stereotypy by LY354740. These data indicate that activation of mGlu2/3 receptors reduces the disruptive effects of NMDA receptor hypofunction on the spontaneous spike activity and bursting of PFC neurons. This mechanism may provide a physiological basis for reversal of NMDA antagonist-induced behaviors by mGlu2/3 agonists.

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