scholarly journals Entrainment and maintenance of an internal metronome in premotor cortex

2018 ◽  
Author(s):  
J Cadena-Valencia ◽  
O García-Garibay ◽  
H Merchant ◽  
M Jazayeri ◽  
V de Lafuente
Keyword(s):  
Neural Activity ◽  
Nonhuman Primates ◽  
Supplementary Motor Area ◽  
Premotor Cortex ◽  
Behavioral Responses ◽  
Elapsed Time ◽  
Neuronal Mechanisms ◽  
Future Events ◽  
Motor Actions ◽  
Premotor Areas

AbstractTo prepare timely motor actions we constantly predict future events. Regularly repeating events are often perceived as a rhythm to which we can readily synchronize our movements, just as in dancing to music. However, the neuronal mechanisms underlying the capacity to encode and maintain rhythms are not understood. We trained nonhuman primates to maintain the rhythm of a visual metronome of different tempos and then we recorded neural activity in the supplementary motor area (SMA). SMA exhibited rhythmic bursts of gamma band (30-40 Hz) reflecting an internal tempo that matched the extinguished visual metronome. Moreover, gamma amplitude increased throughout the trial and provided an estimate of total elapsed time. Notably, the timing and amplitude of gamma bursts reflected systematic timing biases and errors in the behavioral responses. Our results indicate that premotor areas use dynamic motor plans to encode a metronome for rhythms and a stopwatch for total elapsed time.

scholarly journals Entrainment and maintenance of an internal metronome in supplementary motor area

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Jaime Cadena-Valencia ◽  
Otto García-Garibay ◽  
Hugo Merchant ◽  
Mehrdad Jazayeri ◽  
Victor de Lafuente
Keyword(s):  
Firing Rate ◽  
Neural Activity ◽  
Nonhuman Primates ◽  
Supplementary Motor Area ◽  
Gamma Band ◽  
Motor Area ◽  
Elapsed Time ◽  
Neuronal Mechanisms ◽  
Future Events ◽  
Motor Actions

To prepare timely motor actions, we constantly predict future events. Regularly repeating events are often perceived as a rhythm to which we can readily synchronize our movements, just as in dancing to music. However, the neuronal mechanisms underlying the capacity to encode and maintain rhythms are not understood. We trained nonhuman primates to maintain the rhythm of a visual metronome of diverse tempos and recorded neural activity in the supplementary motor area (SMA). SMA exhibited rhythmic bursts of gamma band (30–40 Hz) reflecting an internal tempo that matched the extinguished visual metronome. Moreover, gamma amplitude increased throughout the trial, providing an estimate of total elapsed time. Notably, the timing of gamma bursts and firing rate modulations allowed predicting whether monkeys were ahead or behind the correct tempo. Our results indicate that SMA uses dynamic motor plans to encode a metronome for rhythms and a stopwatch for total elapsed time.

A Comparison of Abstract Rules in the Prefrontal Cortex, Premotor Cortex, Inferior Temporal Cortex, and Striatum

2006 ◽  
Vol 18 (6) ◽  
pp. 974-989 ◽  
Author(s):  
Rahmat Muhammad ◽  
Jonathan D. Wallis ◽  
Earl K. Miller
Keyword(s):  
Prefrontal Cortex ◽  
Neural Activity ◽  
Premotor Cortex ◽  
Temporal Cortex ◽  
Dorsal Striatum ◽  
Behavioral Responses ◽  
Inferior Temporal Cortex ◽  
Perceptual Information ◽  
Lateral Prefrontal Cortex

The ability to use abstract rules or principles allows behavior to generalize from specific circumstances. We have previously shown that such rules are encoded in the lateral prefrontal cortex (PFC) and premotor cortex (PMC). Here, we extend these investigations to two other areas directly connected with the PFC and the PMC, the inferior temporal cortex (ITC) and the dorsal striatum (STR). Monkeys were trained to use two abstract rules: “same” or “different”. They had to either hold or release a lever, depending on whether two successively presented pictures were the same or different, and depending on which rule was in effect. The rules and the behavioral responses were reflected most strongly and, on average, tended to be earlier in the PMC followed by the PFC and then the STR; few neurons in the ITC reflected the rules or the actions. By contrast, perceptual information (the identity of the pictures used as sample and test stimuli) was encoded more strongly and earlier in the ITC, followed by the PFC; they had weak, if any, effects on neural activity in the PMC and STR. These findings are discussed in the context of the anatomy and posited functions of these areas.

scholarly journals The Bilateral Origin of Movement-Related Potentials Preceding Unilateral Actions

2004 ◽  
Vol 18 (2/3) ◽  
pp. 140-148 ◽  
Author(s):  
C.H.M. Brunia ◽  
G.J.M. van Boxtel ◽  
J.D. Speelman
Keyword(s):  
Motor Cortex ◽  
Corpus Callosum ◽  
Nonhuman Primates ◽  
Primary Motor Cortex ◽  
Supplementary Motor Area ◽  
Signal Transmission ◽  
Premotor Cortex ◽  
Volume Conduction ◽  
Related Potentials ◽  
Dominant Part

Abstract It is as yet unclear why a unilateral self-paced movement in human and nonhuman primates is preceded by a bilateral Bereitschaftspotential (BP) or readiness potential (RP). The RP consists of an early symmetrical part (termed BP1 or RP), presumably of supplementary motor area (SMA) origin, and a later contralaterally dominant part (termed BP2 or NS'), to which the primary motor cortex (M1) is thought to contribute. Apart from the SMA there are other motor areas in the mesial cortex, which might provide additional sources for these slow waves. Although bilateral intracortical sources of the RP are found in the premotor cortex ( Sasaki & Gemba, 1991 ), they play nearly any role in most discussions on the RP. Recently the very existence of the ipsilateral RP over MI has been doubted. RP recordings of two patients with an intracerebral electrode in the ventro-intermedius nucleus (Vim) of the thalamus are shown, suggesting that the ipsilateral RP is not the consequence of volume conduction or signal transmission via the corpus callosum. Rather they point to a subcortical source, from where the ipsilateral cortex is activated. Anatomical and recent RP recordings from Vim and subthalamic nucleus seem to support this interpretation.

scholarly journals Free will and neurosurgical resections of the supplementary motor area: a critical review

2021 ◽  
Vol 163 (5) ◽  
pp. 1229-1237 ◽  
Author(s):  
Rickard L Sjöberg
Keyword(s):  
Executive Function ◽  
Free Will ◽  
Corticospinal Tract ◽  
Supplementary Motor Area ◽  
Personal Responsibility ◽  
Motor Area ◽  
Simple Motor ◽  
Motor Actions ◽  
Intense Debate

Abstract Background Research suggests that unconscious activity in the supplementary motor area (SMA) precedes not only certain simple motor actions but also the point at which we become aware of our intention to perform such actions. The extent to which these findings have implications for our understanding of the concepts of free will and personal responsibility has been subject of intense debate during the latest four decades. Methods This research is discussed in relation to effects of neurosurgical removal of the SMA in a narrative review. Results Removal of the SMA typically causes a transient inability to perform non-stimulus-driven, voluntary actions. This condition, known as the SMA syndrome, does not appear to be associated with a loss of sense of volition but with a profound disruption of executive function/cognitive control. Conclusions The role of the SMA may be to serve as a gateway between the corticospinal tract and systems for executive function. Such systems are typically seen as tools for conscious decisions. What is known about effects of SMA resections would thus seem to suggest a view that is compatible with concepts of personal responsibility. However, the philosophical question whether free will exists cannot be definitely resolved on the basis of these observations.

Corticospinal Tract Microstructure Correlates With Beta Oscillatory Activity in the Primary Motor Cortex After Stroke

Stroke ◽  
2021 ◽  
Author(s):  
Robert Schulz ◽  
Marlene Bönstrup ◽  
Stephanie Guder ◽  
Jingchun Liu ◽  
Benedikt Frey ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Fractional Anisotropy ◽  
Primary Motor Cortex ◽  
Supplementary Motor Area ◽  
Premotor Cortex ◽  
Motor Impairment ◽  
Motor Area ◽  
Oscillatory Activity ◽  
Premotor Area ◽  
Beta Power

Background and Purpose: Cortical beta oscillations are reported to serve as robust measures of the integrity of the human motor system. Their alterations after stroke, such as reduced movement-related beta desynchronization in the primary motor cortex, have been repeatedly related to the level of impairment. However, there is only little data whether such measures of brain function might directly relate to structural brain changes after stroke. Methods: This multimodal study investigated 18 well-recovered patients with stroke (mean age 65 years, 12 males) by means of task-related EEG and diffusion-weighted structural MRI 3 months after stroke. Beta power at rest and movement-related beta desynchronization was assessed in 3 key motor areas of the ipsilesional hemisphere that are the primary motor cortex (M1), the ventral premotor area and the supplementary motor area. Template trajectories of corticospinal tracts (CST) originating from M1, premotor cortex, and supplementary motor area were used to quantify the microstructural state of CST subcomponents. Linear mixed-effects analyses were used to relate tract-related mean fractional anisotropy to EEG measures. Results: In the present cohort, we detected statistically significant reductions in ipsilesional CST fractional anisotropy but no alterations in EEG measures when compared with healthy controls. However, in patients with stroke, there was a significant association between both beta power at rest ( P =0.002) and movement-related beta desynchronization ( P =0.003) in M1 and fractional anisotropy of the CST specifically originating from M1. Similar structure-function relationships were neither evident for ventral premotor area and supplementary motor area, particularly with respect to their CST subcomponents originating from premotor cortex and supplementary motor area, in patients with stroke nor in controls. Conclusions: These data suggest there might be a link connecting microstructure of the CST originating from M1 pyramidal neurons and beta oscillatory activity, measures which have already been related to motor impairment in patients with stroke by previous reports.

scholarly journals Spatiotemporal correlation of spinal network dynamics underlying spasms in chronic spinalized mice

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Carmelo Bellardita ◽  
Vittorio Caggiano ◽  
Roberto Leiras ◽  
Vanessa Caldeira ◽  
Andrea Fuchs ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Neural Activity ◽  
Sensory Input ◽  
Mouse Genetics ◽  
Spinal Interneurons ◽  
Neuronal Mechanisms ◽  
Cord Injury ◽  
Motor Neuron Excitability ◽  
Spinal Network ◽  
Opening Up

Spasms after spinal cord injury (SCI) are debilitating involuntary muscle contractions that have been associated with increased motor neuron excitability and decreased inhibition. However, whether spasms involve activation of premotor spinal excitatory neuronal circuits is unknown. Here we use mouse genetics, electrophysiology, imaging and optogenetics to directly target major classes of spinal interneurons as well as motor neurons during spasms in a mouse model of chronic SCI. We find that assemblies of excitatory spinal interneurons are recruited by sensory input into functional circuits to generate persistent neural activity, which interacts with both the graded expression of plateau potentials in motor neurons to generate spasms, and inhibitory interneurons to curtail them. Our study reveals hitherto unrecognized neuronal mechanisms for the generation of persistent neural activity under pathophysiological conditions, opening up new targets for treatment of muscle spasms after SCI.

Functional neuroplasticity in response to cerebello-thalamic injury underpins the clinical presentation of tremor in multiple sclerosis

2019 ◽  
Vol 26 (6) ◽  
pp. 696-705 ◽  
Author(s):  
Frederique MC Boonstra ◽  
Gustavo Noffs ◽  
Thushara Perera ◽  
Vilija G Jokubaitis ◽  
Adam P Vogel ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Supplementary Motor Area ◽  
Clinical Presentation ◽  
Clinical Phenotype ◽  
Premotor Cortex ◽  
Brain Structures ◽  
Lesion Load ◽  
Spiral Drawing ◽  
Brain Changes ◽  
Functional Neuroplasticity

Background: Tremor is present in almost half of multiple sclerosis (MS) patients. The lack of understanding of its pathophysiology is hampering progress in development of treatments. Objectives: To clarify the structural and functional brain changes associated with the clinical phenotype of upper limb tremor in people with MS. Methods: Fifteen healthy controls (46.1 ± 15.4 years), 27 MS participants without tremor (46.7 ± 11.6 years) and 42 with tremor (46.6 ± 11.5 years) were included. Tremor was quantified using the Bain score (0–10) for overall severity, handwriting and Archimedes spiral drawing. Functional magnetic resonance imaging activations were compared between participants groups during performance of a joystick task designed to isolate tremulous movement. Inflammation and atrophy of cerebello-thalamo-cortical brain structures were quantified. Results: Tremor participants were found to have atrophy of the cerebellum and thalamus, and higher ipsilateral cerebellar lesion load compared to participants without tremor ( p < 0.020). We found higher ipsilateral activation in the inferior parietal lobule, the premotor cortex and supplementary motor area in MS tremor participants compared to MS participants without tremor during the joystick task. Finally, stronger activation in those areas was associated with lower tremor severity. Conclusion: Subcortical neurodegeneration and inflammation along the cerebello-thalamo-cortical and cortical functional neuroplasticity contribute to the severity of tremor in MS.

Comparison of Neural Activity in the Supplementary Motor Area and in the Primary Motor Cortex in Monkeys

1991 ◽  
Vol 8 (1) ◽  
pp. 27-44 ◽  
Author(s):  
Chen Dao-fen ◽  
B. Hyland ◽  
V. Maier ◽  
A. Palmeri ◽  
M. Wiesendanger
Keyword(s):  
Motor Cortex ◽  
Neural Activity ◽  
Primary Motor Cortex ◽  
Supplementary Motor Area ◽  
Motor Area
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