scholarly journals Preparing for Speed. Focus on “Preparatory Activity in Premotor and Motor Cortex Reflects the Speed of the Upcoming Reach”

2006 ◽  
Vol 96 (6) ◽  
pp. 2842-2843 ◽  
Author(s):  
Paul Cisek
Keyword(s):  
Motor Cortex ◽  
Preparatory Activity

Preparatory activity in motor cortex reflects learning of local visuomotor skills

2003 ◽  
Vol 6 (8) ◽  
pp. 882-890 ◽  
Author(s):  
Rony Paz ◽  
Thomas Boraud ◽  
Chen Natan ◽  
Hagai Bergman ◽  
Eilon Vaadia
Keyword(s):  
Motor Cortex ◽  
Preparatory Activity ◽  
Visuomotor Skills

scholarly journals Low-Dimensional and Monotonic Preparatory Activity in Mouse Anterior Lateral Motor Cortex

2018 ◽  
Vol 38 (17) ◽  
pp. 4163-4185 ◽  
Author(s):  
Hidehiko K. Inagaki ◽  
Miho Inagaki ◽  
Sandro Romani ◽  
Karel Svoboda
Keyword(s):  
Motor Cortex ◽  
Preparatory Activity ◽  
Low Dimensional

scholarly journals Simultaneous Preparation of Multiple Potential Movements: Opposing Effects of Spatial Proximity Mediated by Premotor and Parietal Cortex

2009 ◽  
Vol 102 (4) ◽  
pp. 2084-2095 ◽  
Author(s):  
Peter Praamstra ◽  
Dimitrios Kourtis ◽  
Kianoush Nazarpour
Keyword(s):  
Motor Cortex ◽  
Distributed Control ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Delay Period ◽  
Spatial Proximity ◽  
Frontoparietal Network ◽  
Neurophysiological Studies ◽  
Preparatory Activity ◽  
Posterior Parietal

Neurophysiological studies in monkey have suggested that premotor and motor cortex may prepare for multiple movements simultaneously, sustained by cooperative and competitive interactions within and between the neural populations encoding different actions. Here, we investigate whether competition between alternative movement directions, manipulated in terms of number and spatial angle, is reflected in electroencephalographic (EEG) measures of (pre)motor cortical activity in humans. EEG was recorded during performance of a center-out pointing task in which response signals were preceded by cues providing prior information in the form of arrows pointing to one or more possible movement targets. Delay-period activity in (pre)motor cortex was modulated in the predicted manner by the number of possible movement directions and by the angle separating them. Response latencies, however, were determined not only by the amplitude of movement-preparatory activity, but also by differences in the duration of stimulus evaluation against the visuospatial memory of the cue, reflected in EEG potentials originating from posterior parietal cortex (PPC). Specifically, the spatial proximity of possible movement targets was processed differently by (pre)motor and posterior parietal cortex. Spatial proximity enhanced the amplitude of (pre)motor cortex preparatory activity during the delay period but delayed evaluation of the response signal in the PPC, thus producing opposite effects on response latency. The latter finding supports distributed control of movement decisions in the frontoparietal network, revealing a feature of distributed control that is of potential significance for the understanding of distracter effects in reaching and pointing.

scholarly journals Disruption of cortical dopaminergic modulation impairs preparatory activity and delays licking initiation

2018 ◽  
Author(s):  
Ke Chen ◽  
Roberto Vincis ◽  
Alfredo Fontanini
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Motor Cortex ◽  
Neural Activity ◽  
Cortical Activity ◽  
Motor Deficits ◽  
Receptor Modulation ◽  
Dopaminergic Modulation ◽  
Preparatory Activity ◽  
Motor Cortical

ABSTRACTDysfunction of motor cortices is thought to contribute to motor disorders such as Parkinson’s disease (PD). However, little is known on the link between cortical dopaminergic loss, abnormalities in motor cortex neural activity and motor deficits. We address the role of dopamine in modulating motor cortical activity by focusing on the anterior lateral motor cortex (ALM) of mice performing a cued-licking task. We first demonstrate licking deficits and concurrent alterations of spiking activity in ALM of mice with unilateral depletion of dopaminergic neurons (i.e., mice injected with 6-OHDA into the medial forebrain bundle). Hemi-lesioned mice displayed delayed licking initiation, shorter duration of licking bouts, and lateral deviation of tongue protrusions. In parallel with these motor deficits, we observed a reduction in the prevalence of cue responsive neurons and altered preparatory activity. Acute and local blockade of D1 receptors in ALM recapitulated some of the key behavioral and neural deficits observed in hemi-lesioned mice. Altogether, our data show a direct relationship between cortical D1 receptor modulation, cue-evoked and preparatory activity in ALM, and licking initiation.SIGNIFICANCE STATEMENTThe link between dopaminergic signaling, motor cortical activity and motor deficits is not fully understood. This manuscript describes alterations in neural activity of the anterior lateral motor cortex (ALM) that correlate with licking deficits in mice with unilateral dopamine depletion or with intra-ALM infusion of dopamine antagonist. The findings emphasize the importance of cortical dopaminergic modulation in motor initiation. These results will appeal not only to researchers interested in cortical control of licking, but also to a broader audience interested in motor control and dopaminergic modulation in physiological and pathological conditions. Specifically, our data suggest that dopamine deficiency in motor cortex could play a role in the pathogenesis of the motor symptoms of Parkinson’s disease.

scholarly journals Cognitive control affects motor learning through local variations in GABA within the primary motor cortex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuki Maruyama ◽  
Masaki Fukunaga ◽  
Sho K. Sugawara ◽  
Yuki H. Hamano ◽  
Tetsuya Yamamoto ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Motor Cortex ◽  
Motor Learning ◽  
Cognitive Control ◽  
Primary Motor Cortex ◽  
Resonance Spectroscopy ◽  
Motor Sequence ◽  
Sensorimotor Network ◽  
Preparatory Activity ◽  
The Right

AbstractThe primary motor cortex (M1) is crucial for motor learning; however, its interaction with other brain areas during motor learning remains unclear. We hypothesized that the fronto-parietal execution network (FPN) provides learning-related information critical for the flexible cognitive control that is required for practice. We assessed network-level changes during sequential finger tapping learning under speed pressure by combining magnetic resonance spectroscopy and task and resting-state functional magnetic resonance imaging. There was a motor learning-related increase in preparatory activity in the fronto-parietal regions, including the right M1, overlapping the FPN and sensorimotor network (SMN). Learning-related increases in M1-seeded functional connectivity with the FPN, but not the SMN, were associated with decreased GABA/glutamate ratio in the M1, which were more prominent in the parietal than the frontal region. A decrease in the GABA/glutamate ratio in the right M1 was positively correlated with improvements in task performance (p = 0.042). Our findings indicate that motor learning driven by cognitive control is associated with local variations in the GABA/glutamate ratio in the M1 that reflects remote connectivity with the FPN, representing network-level motor sequence learning formations.

scholarly journals Low-dimensional and monotonic preparatory activity in mouse anterior lateral motor cortex

2017 ◽  
Author(s):  
Hidehiko K. Inagaki ◽  
Miho Inagaki ◽  
Sandro Romani ◽  
Karel Svoboda
Keyword(s):  
Motor Cortex ◽  
Motor Planning ◽  
Model Organism ◽  
Brain Regions ◽  
Direction Selectivity ◽  
Movement Direction ◽  
Delayed Response ◽  
Preparatory Activity ◽  
Mixed Coding ◽  
Low Dimensional

AbstractNeurons in multiple brain regions fire trains of action potentials anticipating specific movements, but this ‘preparatory activity’ has rarely been compared across behavioral tasks in the same brain region. We compared preparatory activity in auditory and tactile delayed-response tasks, with directional licking as the output. The anterior lateral motor cortex (ALM) is necessary for motor planning in both tasks. Multiple features of ALM preparatory activity during the delay epoch were similar across tasks. First, majority of neurons showed direction-selective activity and spatially intermingled neurons were selective for either movement direction. Second, many cells showed mixed coding of sensory stimulus and licking direction, with a bias toward licking direction. Third, delay activity was largely monotonic and low-dimensional. Fourth, pairs of neurons with similar direction selectivity showed high spike-count correlations. Our study forms the foundation to analyze the neural circuits underlying preparatory activity in a genetically tractable model organism.

scholarly journals Preparatory Activity in Premotor and Motor Cortex Reflects the Speed of the Upcoming Reach

2006 ◽  
Vol 96 (6) ◽  
pp. 3130-3146 ◽  
Author(s):  
Mark M. Churchland ◽  
Gopal Santhanam ◽  
Krishna V. Shenoy
Keyword(s):  
Motor Cortex ◽  
Target Location ◽  
Delay Period ◽  
Target Distance ◽  
Movement Speed ◽  
Target Color ◽  
Dynamic Feature ◽  
Preferred Direction ◽  
Preparatory Activity ◽  
Direction Distance

Neurons in premotor and motor cortex show preparatory activity during an instructed-delay task. It has been suggested that such activity primarily reflects visuospatial aspects of the movement, such as target location or reach direction and extent. We asked whether a more dynamic feature, movement speed, is also reflected. Two monkeys were trained to reach at different speeds (“slow” or “fast,” peak speed being ∼50–100% higher for the latter) depending on target color. Targets were presented in seven directions and at two distances. Of 95 neurons with tuned delay-period activity, 95, 78, and 94% showed a significant influence of direction, distance, and instructed speed, respectively. Average peak modulations with respect to direction, distance and speed were 18, 10, and 11 spikes/s. Although robust, modulations of firing rate with target direction were not necessarily invariant: for 45% of neurons, the preferred direction depended significantly on target distance and/or instructed speed. We collected an additional dataset, examining in more detail the effect of target distance (5 distances from 3 to 12 cm in 2 directions). Of 41 neurons with tuned delay-period activity, 85, 83, and 98% showed a significant impact of direction, distance, and instructed speed. Statistical interactions between the effects of distance and instructed speed were common, but it was nevertheless clear that distance “tuning” was not in general a simple consequence of speed tuning. We conclude that delay-period preparatory activity robustly reflects a nonspatial aspect of the upcoming reach. However, it is unclear whether the recorded neural responses conform to any simple reference frame, intrinsic or extrinsic.

scholarly journals Cerebellar contribution to preparatory activity in motor neocortex

2018 ◽  
Author(s):  
Francois P. Chabrol ◽  
Antonin Blot ◽  
Thomas D. Mrsic-Flogel
Keyword(s):  
Motor Cortex ◽  
Feedback Loop ◽  
Dentate Nucleus ◽  
Excitatory Input ◽  
Climbing Fibre ◽  
Reward Delivery ◽  
Preparatory Activity ◽  
Output Neurons ◽  
Cell Firing ◽  
Motor Thalamus

In motor neocortex, preparatory activity predictive of specific movements is maintained by a positive feedback loop with the thalamus. Motor thalamus receives excitatory input from the cerebellum, which learns to generate predictive signals for motor control. The contribution of this pathway to neocortical preparatory signals remains poorly understood. Here we show that in a virtual reality conditioning task, cerebellar output neurons in the dentate nucleus exhibit preparatory activity similar to that in anterolateral motor cortex prior to reward acquisition. Silencing activity in dentate nucleus by photoactivating inhibitory Purkinje cells in the cerebellar cortex caused robust, short-latency suppression of preparatory activity in anterolateral motor cortex. Our results suggest that preparatory activity is controlled by a learned decrease of Purkinje cell firing in advance of reward under supervision of climbing fibre inputs signalling reward delivery. Thus, cerebellar computations exert a powerful influence on preparatory activity in motor neocortex.

scholarly journals Distinct descending motor cortex pathways and their roles in movement

2017 ◽  
Author(s):  
Michael N. Economo ◽  
Sarada Viswanathan ◽  
Bosiljka Tasic ◽  
Erhan Bas ◽  
Johan Winnubst ◽  
...  
Keyword(s):  
Motor Control ◽  
Motor Cortex ◽  
Pyramidal Tract ◽  
Transcriptional Profiling ◽  
Motor Command ◽  
Delayed Response ◽  
Preparatory Activity ◽  
Output Neurons ◽  
Response Task ◽  
Delayed Response Task

ABSTRACTActivity in motor cortex predicts specific movements, seconds before they are initiated. This preparatory activity has been observed in L5 descending ‘pyramidal tract’ (PT) neurons. A key question is how preparatory activity can be maintained without causing movement, and how preparatory activity is eventually converted to a motor command to trigger appropriate movements. We used single cell transcriptional profiling and axonal reconstructions to identify two types of PT neuron. Both types share projections to multiple targets in the basal ganglia and brainstem. One type projects to thalamic regions that connect back to motor cortex. In a delayed-response task, these neurons produced early preparatory activity that persisted until the movement. The second type projects to motor centers in the medulla and produced late preparatory activity and motor commands. These results indicate that two motor cortex output neurons are specialized for distinct roles in motor control.

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