scholarly journals Testing Basal Ganglia Motor Functions Through Reversible Inactivations in the Posterior Internal Globus Pallidus

2008 ◽  
Vol 99 (3) ◽  
pp. 1057-1076 ◽  
Author(s):  
M. Desmurget ◽  
R. S. Turner
Keyword(s):  
Basal Ganglia ◽  
Globus Pallidus ◽  
Reaction Times ◽  
Movement Direction ◽  
Visually Guided ◽  
Movement Initiation ◽  
Internal Globus Pallidus ◽  
On Line ◽  
Motor Loop ◽  
Target Locations

To test current hypotheses on the contribution of the basal ganglia (BG) to motor control, we examined the effects of muscimol-induced inactivations in the skeletomotor region of the internal globus pallidus (sGPi) on visually directed reaching. Injections were made in two monkeys trained to perform four out-and-back reaching movements in quick succession toward four randomly selected target locations. Following sGPi inactivations the following occurred. 1) Peak velocity and acceleration were decreased in nearly all sessions, whereas movement duration lengthened inconsistently. 2) Reaction times were unaffected on average, although minor changes were observed in several individual sessions. 3) Outward reaches showed a substantial hypometria that correlated closely with bradykinesia, but directional accuracy was unaffected. 4) Endpoint accuracy was preserved for the slow visually guided return movements. 5) No impairments were found in the rapid chaining of out-and-back movements, in the selection or initiation of four independent reaches in quick succession or in the quick on-line correction of initially misdirected reaches. 6) Inactivation-induced reductions in the magnitude of movement-related muscle activity (EMG) correlated with the severity of slowing and hypometria. There was no evidence for inactivation-induced alterations in the relative timing of EMG bursts, excessive cocontraction, or impaired suppression of antagonist EMG. Therefore disconnecting the BG motor pathway consistently produced bradykinesia and hypometria, but seldom affected movement initiation time, feedback-mediated guidance, the capacity to produce iterative reaches, or the ability to abruptly reverse movement direction. These results are discussed with reference to the idea that the BG motor loop may regulate energetic expenditures during movement (i.e., movement “vigor”).

scholarly journals Globus pallidus dynamics reveal covert strategies for behavioral inhibition

2020 ◽  
Author(s):  
Bon-Mi Gu ◽  
Robert Schmidt ◽  
Joshua D. Berke
Keyword(s):  
Basal Ganglia ◽  
State Space ◽  
Globus Pallidus ◽  
Behavioral Inhibition ◽  
Reaction Times ◽  
Proactive Inhibition ◽  
Strategic Positioning ◽  
Movement Initiation ◽  
Population Activity ◽  
Flexible Behavior

AbstractFlexible behavior requires restraint or cancellation of actions that are no longer appropriate. This behavioral inhibition critically relies on frontal cortex - basal ganglia circuits. A central node within the basal ganglia, the globus pallidus pars externa (GPe), has been hypothesized to mediate “proactive” inhibition: being prepared to stop an action if needed. Here we investigate the population dynamics of rat GPe neurons during preparation-to-stop, stopping, and going. Rats could selectively engage proactive inhibition towards one specific action, as shown by slowed reaction times (RTs) for that action. While proactive inhibition was engaged, GPe population activity occupied state-space locations farther from the trajectory followed during normal movement initiation. Furthermore, the specific state-space location was predictive of distinct types of errors: failures to stop, failures to go, and incorrect choices. The slowed RTs on correct proactive trials reflected a starting bias towards the alternative action, which was overcome before making progress towards action initiation. Our results demonstrate that rats can exert cognitive control via strategic positioning of their GPe network state.

scholarly journals Globus pallidus dynamics reveal covert strategies for behavioral inhibition

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Bon-Mi Gu ◽  
Robert Schmidt ◽  
Joshua D Berke
Keyword(s):  
Basal Ganglia ◽  
State Space ◽  
Globus Pallidus ◽  
Behavioral Inhibition ◽  
Reaction Times ◽  
Proactive Inhibition ◽  
Movement Initiation ◽  
Population Activity ◽  
Occupied State ◽  
Flexible Behavior

Flexible behavior requires restraint of actions that are no longer appropriate. This behavioral inhibition critically relies on frontal cortex - basal ganglia circuits. Within the basal ganglia, the globus pallidus pars externa (GPe) has been hypothesized to mediate selective proactive inhibition: being prepared to stop a specific action, if needed. Here we investigate population dynamics of rat GPe neurons during preparation-to-stop, stopping, and going. Rats selectively engaged proactive inhibition towards specific actions, as shown by slowed reaction times (RTs). Under proactive inhibition, GPe population activity occupied state-space locations farther from the trajectory followed during normal movement initiation. Furthermore, the state-space locations were predictive of distinct types of errors: failures-to-stop, failures-to-go, and incorrect choices. Slowed RTs on correct proactive trials reflected starting bias towards the alternative action, which was overcome before progressing towards action initiation. Our results demonstrate that rats can exert cognitive control via strategic adjustments to their GPe network state.

Influence of globus pallidus on arm movements in monkeys. II. Effects of stimulation

1984 ◽  
Vol 52 (2) ◽  
pp. 305-322 ◽  
Author(s):  
F. B. Horak ◽  
M. E. Anderson
Keyword(s):  
Basal Ganglia ◽  
Kainic Acid ◽  
Globus Pallidus ◽  
Visual Target ◽  
Reaction Times ◽  
Arm Movements ◽  
Reaction Time Task ◽  
Inhibitory Process ◽  
Arm Reaching ◽  
Sequential Activation

The effect of changing basal ganglia activity with electrical stimulation in and around the globus pallidus (GP) was studied in monkeys trained to make rapid arm-reaching movements to a visual target in a reaction time task. As was the case following kainic acid (KA) lesions of the globus pallidus (30), stimulation changed movement times (MT) without affecting the pattern of sequential activation of muscles involved in the task or, in most cases, the reaction times (RT). Stimulation in the ventrolateral internal segment of the globus pallidus (GPi) or in the ansa lenticularis reduced movement times, whereas stimulation at many sites in the external pallidal segment (GPe), dorsal GPi, and putamen increased movement times for the contralateral arm. These results are consistent with the hypothesis that arm movements are speeded up when the critical output of GPi is increased and arm movements are slowed down when critical GPi output is reduced, either by an inhibitory process (via stimulation-induced activation of inhibitory elements presynaptic to GPi) or by destroying GPi neurons (via kainic acid). The influence of the basal ganglia on the scaling of electromyographic (EMG) amplitude, as opposed to the spatiotemporal organization of EMG activation, is discussed.

scholarly journals Effects of Visual and Auditory Feedback on Sensorimotor Circuits in the Basal Ganglia

2008 ◽  
Vol 99 (6) ◽  
pp. 3042-3051 ◽  
Author(s):  
Janey Prodoehl ◽  
Hong Yu ◽  
Pooja Wasson ◽  
Daniel M. Corcos ◽  
David E. Vaillancourt
Keyword(s):  
Basal Ganglia ◽  
Globus Pallidus ◽  
Visual Feedback ◽  
Auditory Feedback ◽  
Rate Of Change ◽  
Internal Globus Pallidus ◽  
Feedback Type ◽  
New Findings ◽  
Feedback Modalities ◽  
High Level

Previous work using visual feedback has identified two distinct sensorimotor circuits in the basal ganglia (BG): one that scaled with the duration of force and one that scaled with the rate of change of force. The present study compared functional MRI signal changes in the BG during a grip force task using either visual or auditory feedback to determine whether the BG nuclei process auditory and visual feedback similarly. We confirmed the same two sensorimotor circuits in the BG. Activation in the striatum and external globus pallidus (GPe) scaled linearly with the duration of force under visual and auditory feedback conditions, with similar slopes and intercepts across feedback type. The pattern of signal change for the internal globus pallidus (GPi) and subthalamic nucleus (STN) was nonlinear and parameters of the exponential function were altered by feedback type. Specifically, GPi and STN activation decreased exponentially with the rate of change of force. The rate constant and asymptote of the exponential functions for GPi and STN were greater during auditory than visual feedback. In a comparison of the BOLD signal between BG regions, GPe had the highest percentage of variance accounted for and this effect was preserved for both feedback types. These new findings suggest that neuronal activity of specific BG nuclei is affected by whether the feedback is derived from visual or auditory inputs. Also, the data are consistent with the hypothesis that the GPe has a high level of information convergence from other BG nuclei, which is preserved across different sensory feedback modalities.

scholarly journals Motor cortex can directly drive the globus pallidus neurons in a projection neuron type-dependent manner in the rat

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Fuyuki Karube ◽  
Susumu Takahashi ◽  
Kenta Kobayashi ◽  
Fumino Fujiyama
Keyword(s):  
Basal Ganglia ◽  
Motor Cortex ◽  
Globus Pallidus ◽  
Projection Neuron ◽  
Excitatory Input ◽  
Morphological Observation ◽  
Dependent Manner ◽  
Motor Behaviors ◽  
Connection Probability ◽  
Motor Loop

The basal ganglia are critical for the control of motor behaviors and for reinforcement learning. Here, we demonstrate in rats that primary and secondary motor areas (M1 and M2) make functional synaptic connections in the globus pallidus (GP), not usually thought of as an input site of the basal ganglia. Morphological observation revealed that the density of axonal boutons from motor cortices in the GP was 47% and 78% of that in the subthalamic nucleus (STN) from M1 and M2, respectively. Cortical excitation of GP neurons was comparable to that of STN neurons in slice preparations. FoxP2-expressing arkypallidal neurons were preferentially innervated by the motor cortex. The connection probability of cortico-pallidal innervation was higher for M2 than M1. These results suggest that cortico-pallidal innervation is an additional excitatory input to the basal ganglia, and that it can affect behaviors via the cortex-basal ganglia-thalamus motor loop.

326 Characterization of Synchronization Between Globus Pallidus Neurons and Motor Cortex in Parkinson's Disease

Neurosurgery ◽  
2017 ◽  
Vol 64 (CN_suppl_1) ◽  
pp. 271-272
Author(s):  
Doris D Wang ◽  
Nicki Swann ◽  
Coralie de Hemptinne ◽  
Philip A Starr
Keyword(s):  
Basal Ganglia ◽  
Motor Cortex ◽  
Globus Pallidus ◽  
Field Potentials ◽  
Frequency Range ◽  
Neuronal Synchronization ◽  
Motor Loop ◽  
Beta Oscillation ◽  
Insight Into

Abstract INTRODUCTION Excessive oscillatory neuronal synchronization throughout the basal ganglia thalamocortical motor loop is a hallmark of the Parkinsonian state. This may manifest as spike-spike correlations, coherence between field potentials, or spike-field interactions within or between structures in the circuit. Globus pallidus occupies a central role in basal ganglia processing, but neither internal (GPi) nor external (GPe) globus pallidus is monosynaptically connected to motor cortex. Understanding patterns of M1-pallidal synchronization will provide insight into the possible different roles of GPi and GPe stimulation, compared to STN stimulation, in ameliorating the excessive neuronal synchronization in PD. METHODS Using subdural electrodes and high resolution electrocorticography (ECoG) contacts temporarily placed over motor cortex during DBS implantation and microelectrode recordings, we evaluate the strength and topography of synchronization between pallidal neurons and cortical ECoG potentials in 16 PD patients. RESULTS >Recording from 59 GPe and 42 GPi cells with cortical ECoG field potentials demonstrated that 17% of GPe and 12% of GPi neurons showed significant interactions associated with cortical recording sites approximately 25 mm from midline. For those pairs with significant interactions, peak of the spike-triggered average potentials occurred within 100ms prior to spike time. GPe neurons showed maximum coherence with M1 in the beta (13-30 Hz) frequency range while GPi neurons had maximum coherence in the alpha (8-12 Hz) range. CONCLUSION Topography of significant M1-pallidal interactions is consistent with tractography findings showing more mesial areas of M1 to dominate cortical-basal ganglia anatomic connectivity. The observation that GPe stimulation is more “prokinetic” than GPi stimulation may be explained by the finding that GPe is more synchronized to the cortex in beta frequencies than GPi, as disruption of beta oscillation is important in ameliorating akinesia.

scholarly journals High-frequency oscillations in the internal globus pallidus: a pathophysiological biomarker in Parkinson's disease?

2020 ◽  
Author(s):  
Luke A Johnson ◽  
Joshua E Aman ◽  
Ying Yu ◽  
David Escobar Sanabria ◽  
Jing Wang ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Basal Ganglia ◽  
Globus Pallidus ◽  
High Frequency ◽  
Neural Oscillations ◽  
Field Potentials ◽  
Internal Globus Pallidus ◽  
High Frequency Oscillations ◽  
Deep Brain

AbstractAbnormal oscillatory neural activity in the basal ganglia is thought to play a pathophysiological role in Parkinson’s disease. Many patient studies have focused on beta frequency band (13-35 Hz) local field potential activity in the subthalamic nucleus, however increasing evidence points to alterations in neural oscillations in high frequency ranges (>100 Hz) having pathophysiological relevance. Prior studies have found that power in subthalamic high frequency oscillations (HFOs) is positively correlated with dopamine tone and increased during voluntary movements, implicating these brain rhythms in normal basal ganglia function. Contrary to this idea, in the current study we present a combination of clinical and preclinical data that support the hypothesis that HFOs in the internal globus pallidus (GPi) are a pathophysiological feature of Parkinson’s disease. Spontaneous and movement-related pallidal field potentials were recorded from deep brain stimulation (DBS) leads targeting the GPi in five externalized Parkinson’s disease patients, on and off dopaminergic medication. We identified a prominent oscillatory peak centered at 200-300 Hz in the off-medication rest recordings in all patients. High frequency power increased during movement, and the magnitude of modulation was negatively correlated with bradykinesia. Moreover, high frequency oscillations were significantly attenuated in the on-medication condition, suggesting they are a feature of the parkinsonian condition. To further confirm that GPi high frequency oscillations are characteristic of dopamine depletion, we also collected field potentials from DBS leads chronically implanted in three rhesus monkeys before and after the induction of parkinsonism with the neurotoxin 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP). High frequency oscillations and their modulation during movement were not prominent in the normal condition but emerged in the parkinsonian condition in the monkey model. These data provide the first evidence demonstrating that exaggerated, movement-modulated high frequency oscillations in the internal globus pallidus are a pathophysiological feature of Parkinson’s disease, and motivate additional investigations into the functional roles of high frequency neural oscillations across the basal ganglia-thalamocortical motor circuit and their relationship to motor control in normal and diseased states. These findings also provide rationale for further exploration of these signals for electrophysiological biomarker-based device programming and stimulation strategies in patients receiving deep brain stimulation therapy.

Putaminal Activity for Simple Reactions or Self-Timed Movements

2003 ◽  
Vol 89 (5) ◽  
pp. 2528-2537 ◽  
Author(s):  
Irwin H. Lee ◽  
John A. Assad
Keyword(s):  
Basal Ganglia ◽  
Neuronal Activity ◽  
Time Window ◽  
Important Determinant ◽  
Reaction Times ◽  
Variable Delay ◽  
Cortical Circuits ◽  
Movement Initiation ◽  
The Difference

To examine the role of basal ganglia-cortical circuits in movement initiation, we trained monkeys to make the same arm movements in two ways—in immediate reaction to a randomly timed external cue (cued movements) and also following a variable delay without an explicit initiation signal (self-timed movements). The two movement types were interleaved and balanced in overall timing to allow a direct comparison of activity before and during the movement. Posterior putaminal neurons generally had phasic, movement-related discharges that were comparable for cued and self-timed movements. On cued movements, neuronal activity increased sharply following cue onset. However, for self-timed movements, there was a slow build-up in activity that preceded the phasic discharge. This slow build-up was time-locked to movement and restricted to a narrow time window hundreds of milliseconds before movement. The difference in premovement activity between cued and self-timed trials was present before the earliest cue-onset times and was not related to any differences in the overall time-to-move between the two types of trials. These features suggest that activity evolving in the basal ganglia-cortical circuitry may drive the initiation of movements by increasing until an activity threshold is exceeded. The activity may increase abruptly in response to an external cue or gradually when the timing of movements is determined by the animals themselves rather than an external cue. In this view, small changes in activity that occur in advance of the much larger perimovement neuronal activity may be an important determinant of when movement occurs. In support of this hypothesis, we found that even for cued movements, faster reaction times were associated with slightly higher levels of activity hundreds of milliseconds before movement.

scholarly journals Action planning and control under uncertainty emerge through a desirability-driven competition between parallel encoding motor plans

2021 ◽  
Vol 17 (10) ◽  
pp. e1009429
Author(s):  
Vince Enachescu ◽  
Paul Schrater ◽  
Stefan Schaal ◽  
Vassilios Christopoulos
Keyword(s):  
Reaction Time ◽  
Target Location ◽  
Reaction Times ◽  
Action Planning ◽  
Movement Initiation ◽  
Planning And Control ◽  
Control Under Uncertainty ◽  
And Control ◽  
Target Locations ◽  
The Brain

Living in an uncertain world, nearly all of our decisions are made with some degree of uncertainty about the consequences of actions selected. Although a significant progress has been made in understanding how the sensorimotor system incorporates uncertainty into the decision-making process, the preponderance of studies focus on tasks in which selection and action are two separate processes. First people select among alternative options and then initiate an action to implement the choice. However, we often make decisions during ongoing actions in which the value and availability of the alternatives can change with time and previous actions. The current study aims to decipher how the brain deals with uncertainty in decisions that evolve while acting. To address this question, we trained individuals to perform rapid reaching movements towards two potential targets, where the true target location was revealed only after the movement initiation. We found that reaction time and initial approach direction are correlated, where initial movements towards intermediate locations have longer reaction times than movements that aim directly to the target locations. Interestingly, the association between reaction time and approach direction was independent of the target probability. By modeling the task within a recently proposed neurodynamical framework, we showed that action planning and control under uncertainty emerge through a desirability-driven competition between motor plans that are encoded in parallel.

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