scholarly journals The somatosensory cortex receives information about motor output

2019 ◽  
Vol 5 (7) ◽  
pp. eaaw5388 ◽  
Author(s):  
Tatsuya Umeda ◽  
Tadashi Isa ◽  
Yukio Nishimura
Keyword(s):  
Somatosensory Cortex ◽  
Sensory Feedback ◽  
Somatosensory System ◽  
Motor Output ◽  
Signal Integration ◽  
Movement Initiation ◽  
Online Processing ◽  
Forelimb Muscles ◽  
Behaving Monkeys ◽  
Temporal Profiles

During voluntary movement, the somatosensory system not only passively receives signals from the external world but also actively processes them via interactions with the motor system. However, it is still unclear how and what information the somatosensory system receives during movement. Using simultaneous recordings of activities of the primary somatosensory cortex (S1), the motor cortex (MCx), and an ensemble of afferent neurons in behaving monkeys combined with a decoding algorithm, we reveal the temporal profiles of signal integration in S1. While S1 activity before movement initiation is accounted for by MCx activity alone, activity during movement is accounted for by both MCx and afferent activities. Furthermore, premovement S1 activity encodes information about imminent activity of forelimb muscles slightly after MCx does. Thus, S1 receives information about motor output before the arrival of sensory feedback signals, suggesting that S1 executes online processing of somatosensory signals via interactions with the anticipatory information.

scholarly journals Plastic Changes in Hand Proprioception Following Force-Field Motor Learning

2010 ◽  
Vol 104 (3) ◽  
pp. 1213-1215 ◽  
Author(s):  
Daniel J. Goble ◽  
Joaquin A. Anguera
Keyword(s):  
Motor Learning ◽  
Force Field ◽  
Recent Work ◽  
Recent Article ◽  
Sensory Feedback ◽  
Motor Output ◽  
Feedback Processing ◽  
Plastic Changes ◽  
Proprioceptive Function ◽  
New Evidence

Motor neurophysiologists are placing greater emphasis on sensory feedback processing than ever before. In line with this shift, a recent article by Ostry and colleagues provided timely new evidence that force-field motor learning influences not only motor output, but also proprioceptive sense. In this Neuro Forum, the merits and limitations of Ostry and colleagues are explored in the context of recent work on proprioceptive function, including several recent studies from this journal.

Revisiting parallel and serial processing in the somatosensory system

2007 ◽  
Vol 30 (2) ◽  
pp. 208-209 ◽  
Author(s):  
Preston E. Garraghty
Keyword(s):  
Somatosensory Cortex ◽  
Scientific Community ◽  
Somatosensory System ◽  
Primary Somatosensory Cortex ◽  
Related Issue ◽  
Serial Processing ◽  
Cortical Areas ◽  
Number Of Factors ◽  
In Series

AbstractThe issue of whether information is processed in parallel or in series in the somatosensory system is complicated by a number of factors. Included among these is the failure on the part of the scientific community to reach a consensus as to what actually constitutes the primary somatosensory cortex (SI) in higher primates. A second, related issue is the marked difference in the organization of the cortical areas subserving somatosensation across species.

A neural link between feeling and hearing

2012 ◽  
Vol 25 (0) ◽  
pp. 56
Author(s):  
Tony Ro ◽  
Timothy Ellmore ◽  
Michael S. Beauchamp
Keyword(s):  
Somatosensory Cortex ◽  
Diffusion Tensor ◽  
Somatosensory System ◽  
Primary Auditory Cortex ◽  
Neural Substrates ◽  
Secondary Somatosensory Cortex ◽  
Anatomical Basis ◽  
Multisensory Interactions ◽  
Bodily Sensations ◽  
White Matter Connectivity

Hearing and feeling both rely upon the transduction of physical events into frequency-based neural codes, suggesting that the auditory system may be intimately related to the somatosensory system. In this study, we provide evidence that the neural substrates for audition and somatosensation are anatomically linked. Using diffusion tensor imaging with both deterministic and probabilistic tractography to measure white matter connectivity, we show that there are extensive connections between the primary auditory cortex and the primary and secondary somatosensory regions in human cerebral cortex. We further show that these cross-connections are diminished between auditory and primary somatosensory cortex and exaggerated between auditory and secondary somatosensory cortex in the lesioned hemisphere of a patient (SR) with acquired auditory-tactile synesthesia, in whom sounds alone produce bodily sensations. These results provide an anatomical basis for multisensory interactions between audition and somatosensation and suggest that cross-talk between these regions may explain why some sounds, such as nails screeching down a chalkboard or an audible mosquito, can induce feelings of touch, especially on the left half of patient SR.

scholarly journals Decreased Cortical Serotonin in Neonatal Rabbits Exposed to Endotoxin in Utero

2010 ◽  
Vol 31 (2) ◽  
pp. 738-749 ◽  
Author(s):  
Sujatha Kannan ◽  
Fadoua Saadani-Makki ◽  
Bindu Balakrishnan ◽  
Hui Dai ◽  
Pulak K Chakraborty ◽  
...  
Keyword(s):  
Somatosensory Cortex ◽  
Neurodevelopmental Disorders ◽  
Somatosensory System ◽  
Fold Increase ◽  
Standard Uptake Value ◽  
Perinatal Period ◽  
Newborn Brain ◽  
Positron Emission ◽  
Parietal Cortices

Maternal intrauterine inflammation is implicated in neurodevelopmental disorders in the offspring. Serotonin is crucial for regulating maturation in the developing brain, and maternal inflammation may result in disruption of the serotonergic system in the perinatal period. Saline or endotoxin was injected intrauterine in pregnant rabbits term. Newborn rabbits underwent positron emission tomography (PET) imaging with α[11C]methyl-l-tryptophan (AMT) to evaluate tryptophan metabolism in vivo. Decrease in standard uptake value for AMT and decrease in serotonin concentration was noted in the frontal and parietal cortices of endotoxin kits when compared with controls. In addition, a significant decrease in serotonin-immunoreactive fibers and decreased expression of serotonin transporter (5HTT) was measured in the somatosensory cortex. There was a three-fold increase in the number of apoptotic cells in the ventrobasal (VB) thalamus without loss of raphe serotonergic cell bodies in endotoxin kits when compared with controls. Glutamateric VB neurons projecting to somatosensory cortex transiently express 5HTT and store serotonin, regulating development of the somatosensory cortex. Intrauterine inflammation results in alterations in cortical serotonin and disruption of serotonin-regulated thalamocortical development in the newborn brain. This may be a common link in neurodevelopmental disorders resulting in impairment of the somatosensory system, such as cerebral palsy and autism.

scholarly journals Rotational dynamics in motor cortex are consistent with a feedback controller

2020 ◽  
Author(s):  
Hari Teja Kalidindi ◽  
Kevin P. Cross ◽  
Timothy P. Lillicrap ◽  
Mohsen Omrani ◽  
Egidio Falotico ◽  
...  
Keyword(s):  
Neural Networks ◽  
Motor Cortex ◽  
Somatosensory Cortex ◽  
Sensory Feedback ◽  
Feedback Controller ◽  
Rotational Dynamics ◽  
Rotational Structure ◽  
List Type ◽  
Neurophysiological Studies ◽  
Recurrent Connections

SummaryRecent studies hypothesize that motor cortical (MC) dynamics are generated largely through its recurrent connections based on observations that MC activity exhibits rotational structure. However, behavioural and neurophysiological studies suggest that MC behaves like a feedback controller where continuous sensory feedback and interactions with other brain areas contribute substantially to MC processing. We investigated these apparently conflicting theories by building recurrent neural networks that controlled a model arm and received sensory feedback about the limb. Networks were trained to counteract perturbations to the limb and to reach towards spatial targets. Network activities and sensory feedback signals to the network exhibited rotational structure even when the recurrent connections were removed. Furthermore, neural recordings in monkeys performing similar tasks also exhibited rotational structure not only in MC but also in somatosensory cortex. Our results argue that rotational structure may reflect dynamics throughout voluntary motor circuits involved in online control of motor actions.HighlightsNeural networks with sensory feedback generate rotational dynamics during simulated posture and reaching tasksRotational dynamics are observed even without recurrent connections in the networkSimilar dynamics are observed not only in motor cortex, but also in somatosensory cortex of non-huma n primates as well as sensory feedback signalsResults highlight rotational dynamics may reflect internal dynamics, external inputs or any combination of the two.

Reflex Organization in the Swimmeret System of the Lobster

1969 ◽  
Vol 51 (3) ◽  
pp. 547-563
Author(s):  
W. J. DAVIS
Keyword(s):  
Sensory Feedback ◽  
Motor Command ◽  
Homarus Americanus ◽  
Motor Output ◽  
Motor Patterns ◽  
Motor Neurones ◽  
Output Pattern

1. The intrasegmental feedback reflexes in the swimmeret system of the lobster Homarus americanus were activated while recording the responses from the swimmeret nerves and muscles. 2. Two main sources of sensory feedback were identified; proprioceptors in the coxal region of the swimmeret, and sensory setae on the edges of the two rami of each swimmeret. The reflexes activated by these inputs are described. 3. Reflexive feedback from the powerstroke movement to the powerstroke excita tory motor neurones is positive, further reinforcing the movement. Intrasegmental reflexes capable of independently initiating or terminating the powerstroke activity are absent, however. Therefore the powerstroke movement of each cycle can begin and end only in response to a purely central nervous motor command. It follows that the intrasegmental swimmeret reflexes are incapable of contributing to the periodicity seen in the motor output pattern which underlies swimmeret beating. 4. In addition to strengthening the powerstroke, the intrasegmental reflexes strengthen the linkage between the powerstroke and the returnstroke within each movement cycle. The reflexes may also reinforce the reciprocity between excitor and inhibitor axon activity to the main powerstroke and returnstroke muscles. 5. It is shown, however, that these three features of the motor output pattern are programmed into the CNS independently of the sensory feedback. The intrasegmental reflexes thus act as subservient amplifying devices for cyclic motor patterns which are produced independently by purely central nervous mechanisms.

Primary somatosensory cortex hand representation dynamically modulated by motor output

Neurocase ◽  
2014 ◽  
Vol 21 (1) ◽  
pp. 103-105 ◽  
Author(s):  
Paul D. McGeoch ◽  
David Brang ◽  
Mingxiong Huang ◽  
V.S. Ramachandran
Keyword(s):  
Somatosensory Cortex ◽  
Motor Output ◽  
Primary Somatosensory Cortex

scholarly journals An In Vitro Spinal Cord–Hindlimb Preparation for Studying Behaviorally Relevant Rat Locomotor Function

2009 ◽  
Vol 101 (2) ◽  
pp. 1114-1122 ◽  
Author(s):  
Heather Brant Hayes ◽  
Young-Hui Chang ◽  
Shawn Hochman
Keyword(s):  
Spinal Cord ◽  
Sensory Feedback ◽  
Muscle Activation ◽  
Motor Pattern ◽  
Motor Output ◽  
Afferent Feedback ◽  
Neonatal Rat ◽  
Stride Frequency ◽  
Muscle Activation Patterns

Although the spinal cord contains the pattern-generating circuitry for producing locomotion, sensory feedback reinforces and refines the spatiotemporal features of motor output to match environmental demands. In vitro preparations, such as the isolated rodent spinal cord, offer many advantages for investigating locomotor circuitry, but they lack the natural afferent feedback provided by ongoing locomotor movements. We developed a novel preparation consisting of an isolated in vitro neonatal rat spinal cord oriented dorsal-up with intact hindlimbs free to step on a custom-built treadmill. This preparation combines the neural accessibility of in vitro preparations with the modulatory influence of sensory feedback from physiological hindlimb movement. Locomotion induced by N-methyl d-aspartate and serotonin showed kinematics similar to that of normal adult rat locomotion. Changing orientation and ground interaction (dorsal-up locomotion vs ventral-up air-stepping) resulted in significant kinematic and electromyographic changes that were comparable to those reported under similar mechanical conditions in vivo. We then used two mechanosensory perturbations to demonstrate the influence of sensory feedback on in vitro motor output patterns. First, swing assistive forces induced more regular, robust muscle activation patterns. Second, altering treadmill speed induced corresponding changes in stride frequency, confirming that changes in sensory feedback can alter stride timing in vitro. In summary, intact hindlimbs in vitro can generate behaviorally appropriate locomotor kinematics and responses to sensory perturbations. Future studies combining the neural and chemical accessibility of the in vitro spinal cord with the influence of behaviorally appropriate hindlimb movements will provide further insight into the operation of spinal motor pattern-generating circuits.

scholarly journals The ‘creatures’ of the human cortical somatosensory system

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Noam Saadon-Grosman ◽  
Yonatan Loewenstein ◽  
Shahar Arzy
Keyword(s):  
Somatosensory Cortex ◽  
Somatosensory System ◽  
Brain Regions ◽  
Human Cognition ◽  
Whole Body ◽  
Functional Specialization ◽  
Body Parts ◽  
Somatosensory Processing ◽  
Somatosensory Stimulation ◽  
Cortical Parcellation

Abstract Penfield’s description of the ‘homunculus’, a ‘grotesque creature’ with large lips and hands and small trunk and legs depicting the representation of body-parts within the primary somatosensory cortex (S1), is one of the most prominent contributions to the neurosciences. Since then, numerous studies have identified additional body-parts representations outside of S1. Nevertheless, it has been implicitly assumed that S1’s homunculus is representative of the entire somatosensory cortex. Therefore, the distribution of body-parts representations in other brain regions, the property that gave Penfield’s homunculus its famous ‘grotesque’ appearance, has been overlooked. We used whole-body somatosensory stimulation, functional MRI and a new cortical parcellation to quantify the organization of the cortical somatosensory representation. Our analysis showed first, an extensive somatosensory response over the cortex; and second, that the proportional representation of body parts differs substantially between major neuroanatomical regions and from S1, with, for instance, much larger trunk representation at higher brain regions, potentially in relation to the regions’ functional specialization. These results extend Penfield’s initial findings to the higher level of somatosensory processing and suggest a major role for somatosensation in human cognition.

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