scholarly journals Central processing of leg proprioception in Drosophila

2020 ◽  
Author(s):  
Sweta Agrawal ◽  
Evyn S Dickinson ◽  
Anne Sustar ◽  
Pralaksha Gurung ◽  
David Shepherd ◽  
...  
Keyword(s):  
Joint Angle ◽  
Sense Of Self ◽  
Sensory Information ◽  
Cell Types ◽  
Proprioceptive Information ◽  
Central Processing ◽  
Directional Movement ◽  
Postural Changes ◽  
Limb Posture ◽  
To Receive

AbstractProprioception, the sense of self-movement and position, is mediated by mechanosensory neurons that detect diverse features of body kinematics. Although proprioceptive feedback is crucial for accurate motor control, little is known about how downstream circuits transform limb sensory information to guide motor output. Here, we investigate neural circuits in Drosophila that process proprioceptive information from the fly leg. We identify three cell-types from distinct developmental lineages that are positioned to receive input from proprioceptor subtypes encoding tibia position, movement, and vibration. 13Bα neurons encode femur-tibia joint angle and mediate postural changes in tibia position. 9Aα neurons also drive changes in leg posture, but encode a combination of directional movement, high frequency vibration, and joint angle. Activating 10Bα neurons, which encode tibia vibration at specific joint angles, elicits pausing in walking flies. Altogether, our results reveal that central circuits integrate information across proprioceptor subtypes to construct complex sensorimotor representations that mediate diverse behaviors, including reflexive control of limb posture and detection of leg vibration.

scholarly journals Central processing of leg proprioception in Drosophila

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Sweta Agrawal ◽  
Evyn S Dickinson ◽  
Anne Sustar ◽  
Pralaksha Gurung ◽  
David Shepherd ◽  
...  
Keyword(s):  
Joint Angle ◽  
Sense Of Self ◽  
Sensory Information ◽  
Cell Types ◽  
Proprioceptive Information ◽  
Central Processing ◽  
Directional Movement ◽  
Postural Changes ◽  
Limb Posture ◽  
To Receive

Proprioception, the sense of self-movement and position, is mediated by mechanosensory neurons that detect diverse features of body kinematics. Although proprioceptive feedback is crucial for accurate motor control, little is known about how downstream circuits transform limb sensory information to guide motor output. Here we investigate neural circuits in Drosophila that process proprioceptive information from the fly leg. We identify three cell types from distinct developmental lineages that are positioned to receive input from proprioceptor subtypes encoding tibia position, movement, and vibration. 13Bα neurons encode femur-tibia joint angle and mediate postural changes in tibia position. 9Aα neurons also drive changes in leg posture, but encode a combination of directional movement, high frequency vibration, and joint angle. Activating 10Bα neurons, which encode tibia vibration at specific joint angles, elicits pausing in walking flies. Altogether, our results reveal that central circuits integrate information across proprioceptor subtypes to construct complex sensorimotor representations that mediate diverse behaviors, including reflexive control of limb posture and detection of leg vibration.

scholarly journals The Role of Ankle Proprioception for Balance Control in relation to Sports Performance and Injury

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jia Han ◽  
Judith Anson ◽  
Gordon Waddington ◽  
Roger Adams ◽  
Yu Liu
Keyword(s):  
Sports Injuries ◽  
Balance Control ◽  
Sensory Information ◽  
Proprioceptive Information ◽  
Central Processing ◽  
Processing Theory ◽  
The Central Nervous System ◽  
Sports And Exercise ◽  
Ankle Proprioception

Balance control improvement is one of the most important goals in sports and exercise. Better balance is strongly positively associated with enhanced athletic performance and negatively associated with lower limb sports injuries. Proprioception plays an essential role in balance control, and ankle proprioception is arguably the most important. This paper reviews ankle proprioception and explores synergies with balance control, specifically in a sporting context. Central processing of ankle proprioceptive information, along with other sensory information, enables integration for balance control. When assessing ankle proprioception, the most generalizable findings arise from methods that are ecologically valid, allow proprioceptive signals to be integrated with general vision in the central nervous system, and reflect the signal-in-noise nature of central processing. Ankle proprioceptive intervention concepts driven by such a central processing theory are further proposed and discussed for the improvement of balance control in sport.

Postural sway with earth-fixed and body-referenced finger contact in young and older adults

1999 ◽  
Vol 9 (2) ◽  
pp. 103-109
Author(s):  
Reginald L. Reginella ◽  
Mark S. Redfern ◽  
Joseph M. Furman
Keyword(s):  
Older Adults ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Sensory Information ◽  
Body Sway ◽  
Support Surface ◽  
Proprioceptive Information ◽  
Postural Control System ◽  
Fixed Reference ◽  
Older Subjects

Sensory information from lightly touching a reference with the hand is known to influence postural sway in young adults. The primary aim of this study was to compare the influence of finger contact (FC) with an earth-fixed reference to the influence of FC with a body-fixed reference. A second goal of this study was to determine if FC is used differently by older adults compared to younger adults. Using a force plate, center of pressure at the feet was recorded from blindfolded young and older subjects during several conditions. Subjects either did or did not lightly touch a force-sensitive plate that was either earth-fixed or moved forward and backward in synchrony with body sway (that is, sway-referenced). In addition, support surface conditions were also varied, including a fixed floor and a sway-referenced floor using an EquitestTM. Results showed that the type of FC, floor condition, and age each had an effect on postural sway. Touching an earth-fixed plate decreased postural sway as compared to no touching, while touching a sway-referenced plate incresased sway. This influence of FC was enhanced when the floor was sway-referenced. Although older subjects swayed more than young subjects overall, no age-FC interactions occurred, indicating that FC was not utilized differently between the age groups. This study suggests that FC cannot be disregarded as erroneous, especially when proprioceptive information from the legs is distorted. Further, FC is integrated with other sensory information by the postural control system similarly in young and older persons.

P4995Neuregulin-1 compensates for endothelial NO synthase deficiency in the heart and kidney

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
H Shakeri ◽  
S De Moudt ◽  
A J Leloup ◽  
G Jacobs ◽  
G R Y De Meyer ◽  
...  
Keyword(s):  
Renal Fibrosis ◽  
Cell Types ◽  
Cardiovascular Development ◽  
Wild Type ◽  
Negative Effects ◽  
Knock Out ◽  
Neuregulin 1 ◽  
Cardioprotective Effects ◽  
To Receive ◽  
Knock Out Mouse

Abstract Background Decreased eNOS activity is the hallmark of endothelial dysfunction and is associated with cardiovascular and renal disorders. Besides NO, endothelial cells produce numerous other small molecules, peptides, and proteins, which modulate the function of adjacent cells. For instance, neuregulin-1 (NRG-1) is an endothelium-derived growth factor, which plays crucial roles in cardiovascular development, has cardioprotective properties, and induces growth and differentiation of cell types in different organs, including the kidney. Purpose Although the cardioprotective effects of endothelium-derived NO and NRG-1 are well established, their interaction is not clear. Therefore, we studied the interaction between the NO/eNOS and NRG-1/ErbB signalling pathways in a transgenic eNOS knock-out mouse model (eNOS−/−) treated with subpressor doses of angiotensin II (AngII). Methods eNOS−/− mice and their wild type (WT) littermates (n=64, 15 weeks old) were randomized for implantation of osmotic minipumps with AngII (400 ng/kg.min) for 28 days or sham surgery. Mice were randomized to receive either daily NRG-1 injections (20 μg/kg, intraperitoneal) or vehicle for 4 weeks (n=8/group). Hypertrophy and fibrosis were measured in left ventricle (LV) and kidneys using echography and immunohistochemical staining. Results Although blood pressure was higher in eNOS−/− mice compared to their WT littermates, it was unaffected by a subpressor dose of AngII. Masson's trichrome staining showed that AngII significantly increased LV (interstitial and perivascular) and renal fibrosis in eNOS−/− mice, but not in WT controls (see figure for LV data). NRG-1 reversed this AngII-induced LV and renal fibrosis caused by eNOS deficiency. There was also significant hypertrophy of LV and kidneys in eNOS−/− mice treated with AngII, which was again normalized by NRG-1 treatment. Moreover, NRG-1 significantly attenuated albuminuria induced by eNOS deficiency under AngII treatment. Conclusions This study demonstrates that the anti-fibrotic and anti-hypertrophic effects of NRG-1 are independent from the NO/eNOS pathway in both heart and kidney. Strikingly, NRG-1 is able to compensate for some of the negative effects of eNOS deficiency, at least in conditions of AngII stimulation. Acknowledgement/Funding supported by university of Antwerp

Multisensory Integration and the Perception of Self-Motion

2018 ◽  
Author(s):  
Kathleen E. Cullen
Keyword(s):  
Rotational Velocity ◽  
Sensory Information ◽  
Proprioceptive Information ◽  
Everyday Activities ◽  
Perceptual Stability ◽  
The World ◽  
Perception Of Self ◽  
Self Motion ◽  
The Brain ◽  
Vestibular Pathways

As we go about our everyday activities, our brain computes accurate estimates of both our motion relative to the world, and of our orientation relative to gravity. Essential to this computation is the information provided by the vestibular system; it detects the rotational velocity and linear acceleration of our heads relative to space, making a fundamental contribution to our perception of self-motion and spatial orientation. Additionally, in everyday life, our perception of self-motion depends on the integration of both vestibular and nonvestibular cues, including visual and proprioceptive information. Furthermore, the integration of motor-related information is also required for perceptual stability, so that the brain can distinguish whether the experienced sensory inflow was a result of active self-motion through the world or if instead self-motion that was externally generated. To date, understanding how the brain encodes and integrates sensory cues with motor signals for the perception of self-motion during natural behaviors remains a major goal in neuroscience. Recent experiments have (i) provided new insights into the neural code used to represent sensory information in vestibular pathways, (ii) established that vestibular pathways are inherently multimodal at the earliest stages of processing, and (iii) revealed that self-motion information processing is adjusted to meet the needs of specific tasks. Our current level of understanding of how the brain integrates sensory information and motor-related signals to encode self-motion and ensure perceptual stability during everyday activities is reviewed.

scholarly journals Proprioceptive Acuity Assessment Via Joint Position Matching: From Basic Science to General Practice

2010 ◽  
Vol 90 (8) ◽  
pp. 1176-1184 ◽  
Author(s):  
Daniel J. Goble
Keyword(s):  
General Practice ◽  
Basic Science ◽  
Joint Angle ◽  
Critical Role ◽  
Clinical Settings ◽  
Proprioceptive Information ◽  
Joint Position ◽  
Subsequent Recovery ◽  
Dependent Plasticity ◽  
The Past

Over the past several decades, studies of use-dependent plasticity have demonstrated a critical role for proprioceptive feedback in the reorganization, and subsequent recovery, of neuromotor systems. As such, an increasing emphasis has been placed on tests of proprioceptive acuity in both the clinic and the laboratory. One test that has garnered particular interest is joint position matching, whereby individuals must replicate a reference joint angle in the absence of vision (ie, using proprioceptive information). On the surface, this test might seem straightforward in nature. However, the present perspective article informs therapists and researchers alike of multiple insights gained from a recent series of position matching studies by the author and colleagues. In particular, 5 factors are outlined that can assist clinicians in developing well-informed opinions regarding the outcomes of tests of position matching abilities. This information should allow for enhanced diagnosis of proprioceptive deficits within clinical settings in the future.

scholarly journals Reinforcement Learning of Two-Joint Virtual Arm Reaching in a Computer Model of Sensorimotor Cortex

2013 ◽  
Vol 25 (12) ◽  
pp. 3263-3293 ◽  
Author(s):  
Samuel A. Neymotin ◽  
George L. Chadderdon ◽  
Cliff C. Kerr ◽  
Joseph T. Francis ◽  
William W. Lytton
Keyword(s):  
Reinforcement Learning ◽  
Information Flow ◽  
Sensory Information ◽  
Relevant Information ◽  
Spike Timing ◽  
Proprioceptive Information ◽  
Learning Networks ◽  
Neuronal Populations ◽  
Arm Reaching

Neocortical mechanisms of learning sensorimotor control involve a complex series of interactions at multiple levels, from synaptic mechanisms to cellular dynamics to network connectomics. We developed a model of sensory and motor neocortex consisting of 704 spiking model neurons. Sensory and motor populations included excitatory cells and two types of interneurons. Neurons were interconnected with AMPA/NMDA and GABAA synapses. We trained our model using spike-timing-dependent reinforcement learning to control a two-joint virtual arm to reach to a fixed target. For each of 125 trained networks, we used 200 training sessions, each involving 15 s reaches to the target from 16 starting positions. Learning altered network dynamics, with enhancements to neuronal synchrony and behaviorally relevant information flow between neurons. After learning, networks demonstrated retention of behaviorally relevant memories by using proprioceptive information to perform reach-to-target from multiple starting positions. Networks dynamically controlled which joint rotations to use to reach a target, depending on current arm position. Learning-dependent network reorganization was evident in both sensory and motor populations: learned synaptic weights showed target-specific patterning optimized for particular reach movements. Our model embodies an integrative hypothesis of sensorimotor cortical learning that could be used to interpret future electrophysiological data recorded in vivo from sensorimotor learning experiments. We used our model to make the following predictions: learning enhances synchrony in neuronal populations and behaviorally relevant information flow across neuronal populations, enhanced sensory processing aids task-relevant motor performance and the relative ease of a particular movement in vivo depends on the amount of sensory information required to complete the movement.

Reference Frames for Spinal Proprioception: Limb Endpoint Based or Joint-Level Based?

2000 ◽  
Vol 83 (5) ◽  
pp. 2931-2945 ◽  
Author(s):  
G. Bosco ◽  
R. E. Poppele ◽  
J. Eian
Keyword(s):  
Regression Model ◽  
Neuronal Activity ◽  
Reference Frames ◽  
Joint Angle ◽  
Cell Activity ◽  
Proprioceptive Information ◽  
Joint Angles ◽  
Indicator Variable ◽  
Mechanical Constraints ◽  
Foot Position

Many sensorimotor neurons in the CNS encode global parameters of limb movement and posture rather than specific muscle or joint parameters. Our investigations of spinocerebellar activity have demonstrated that these second-order spinal neurons also may encode proprioceptive information in a limb-based rather than joint-based reference frame. However, our finding that each foot position was determined by a unique combination of joint angles in the passive limb made it difficult to distinguish unequivocally between a limb-based and a joint-based representation. In this study, we decoupled foot position from limb geometry by applying mechanical constraints to individual hindlimb joints in anesthetized cats. We quantified the effect of the joint constraints on limb geometry by analyzing joint-angle covariance in the free and constrained conditions. One type of constraint, a rigid constraint of the knee angle, both changed the covariance pattern and significantly reduced the strength of joint-angle covariance. The other type, an elastic constraint of the ankle angle, changed only the covariance pattern and not its overall strength. We studied the effect of these constraints on the activity in 70 dorsal spinocerebellar tract (DSCT) neurons using a multivariate regression model, with limb axis length and orientation as predictors of neuronal activity. This model also included an experimental condition indicator variable that allowed significant intercept or slope changes in the relationships between foot position parameters and neuronal activity to be determined across conditions. The result of this analysis was that the spatial tuning of 37/70 neurons (53%) was unaffected by the constraints, suggesting that they were somehow able to signal foot position independently from the specific joint angles. We also investigated the extent to which cell activity represented individual joint angles by means of a regression model based on a linear combination of joint angles. A backward elimination of the insignificant predictors determined the set of independent joint angles that best described the neuronal activity for each experimental condition. Finally, by comparing the results of these two approaches, we could determine whether a DSCT neuron represented foot position, specific joint angles, or none of these variables consistently. We found that 10/70 neurons (14%) represented one or more specific joint-angles. The activity of another 27 neurons (39%) was significantly affected by limb geometry changes, but 33 neurons (47%) consistently elaborated a foot position representation in the coordinates of the limb axis.

scholarly journals Two dynamically distinct circuits driving inhibition in sensory thalamus

2020 ◽  
Author(s):  
Rosa I. Martinez-Garcia ◽  
Bettina Voelcker ◽  
Julia B. Zaltsman ◽  
Saundra L. Patrick ◽  
Tanya R. Stevens ◽  
...  
Keyword(s):  
Sensory Information ◽  
Cell Types ◽  
Higher Order ◽  
Inhibitory Neurons ◽  
Thalamic Reticular Nucleus ◽  
Reticular Nucleus ◽  
Order Structure ◽  
Multiple Sources ◽  
Cell Groups ◽  
And Function

AbstractMost sensory information destined for the neocortex is relayed through the thalamus, where considerable transformation occurs1,2. One powerful means of transformation involves interactions between excitatory thalamocortical neurons that carry data to cortex and inhibitory neurons of the thalamic reticular nucleus (TRN) that regulate flow of those data3-6. Despite enduring recognition of its importance7-9, understanding of TRN cell types, their organization, and their functional properties has lagged that of the thalamocortical systems they control.Here we address this, investigating somatosensory and visual circuits of the TRN. In the somatosensory TRN we observed two groups of genetically defined neurons that are topographically segregated, physiologically distinct, and connect reciprocally with independent thalamocortical nuclei via dynamically divergent synapses. Calbindin-expressing cells, located in the central core, connect with the ventral posterior nucleus (VP), the primary somatosensory thalamocortical relay. In contrast, somatostatin-expressing cells, residing along the surrounding edges of TRN, synapse with the posterior medial thalamic nucleus (POM), a higher-order structure that carries both top-down and bottom-up information10-12. The two TRN cell groups process their inputs in pathway-specific ways. Synapses from VP to central TRN cells transmit rapid excitatory currents that depress deeply during repetitive activity, driving phasic spike output. Synapses from POM to edge TRN cells evoke slower, less depressing excitatory currents that drive more persistent spiking. Differences in intrinsic physiology of TRN cell types, including state-dependent bursting, contribute to these output dynamics. Thus, processing specializations of two somatosensory TRN subcircuits appear to be tuned to the signals they carry—a primary central subcircuit to discrete sensory events, and a higher-order edge subcircuit to temporally distributed signals integrated from multiple sources. The structure and function of visual TRN subcircuits closely resemble those of the somatosensory TRN. These results provide fundamental insights about how subnetworks of TRN neurons may differentially process distinct classes of thalamic information.

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