Encoding of near-range spatial information by descending interneurons in the stick insect antennal mechanosensory pathway

2013 ◽  
Vol 110 (9) ◽  
pp. 2099-2112 ◽  
Author(s):  
Jan M. Ache ◽  
Volker Dürr
Keyword(s):  
Joint Angle ◽  
Spatial Information ◽  
Strong Dependence ◽  
Movement Direction ◽  
Neural Basis ◽  
Reach To Grasp ◽  
Movement Velocity ◽  
Spatial Coordinate ◽  
Descending Interneurons ◽  
Position Sensitive

Much like mammals use their whiskers, insects use their antennae for tactile near-range orientation during locomotion. Stick insects rapidly transfer spatial information about antennal touch location to the front legs, allowing for aimed reach-to-grasp movements. This adaptive behavior requires a spatial coordinate transformation from “antennal contact space” to “leg posture space.” Therefore, a neural pathway must convey proprioceptive and tactile information about antennal posture and contact site to thoracic motor networks. Here we analyze proprioceptive encoding properties of descending interneurons (DINs) that convey information about antennal posture and movement to the thoracic ganglia. On the basis of response properties of 110 DINs to imposed movement of the distal antennal joint, we distinguish five functional DIN groups according to their sensitivity to three parameters: movement direction, movement velocity, and antennal joint angle. These groups are simple position-sensitive DINs, which signal the antennal joint angle; dynamic position-sensitive DINs, which signal the joint angle with strong dependence on movement; unspecific movement-sensitive DINs, which signal movement but not the velocity, position, or direction of movement; and ON- and OFF-type velocity-sensitive DINs. The activity of the latter two groups is increased/attenuated during antennal movement, with the spike rate increasing/decreasing linearly with antennal joint angle velocity. Some movement-sensitive DINs convey spikes to the thorax within 11 ms, suggesting a rapid, direct pathway from antennal mechanosensory to thoracic motor networks. We discuss how the population of DINs could provide the neural basis for the intersegmental spatial coordinate transfer between a touch sensor of the head and thoracic motor networks.

Input of hair field afferents to a descending interneuron

2021 ◽  
Author(s):  
Bianca Jaske ◽  
Gaetan Lepreux ◽  
Volker Dürr
Keyword(s):  
Joint Angle ◽  
Stick Insect ◽  
Passive Movement ◽  
Activity Level ◽  
Reach To Grasp ◽  
Movement Velocity ◽  
Before And After ◽  
Steady State Activity ◽  
Transfer Of Information ◽  
Antennal Contact

In insects the tactile sense is important for near-range orientation and is involved in various behaviors. Nocturnal insects such as the stick insect Carausius morosus continuously explore their surroundings by actively moving their antennae when walking. Upon antennal contact with objects, stick insects show a targeted front-leg movement. As this reaction occurs within 40 ms, descending transfer of information from the brain to the thorax needs to be fast. So far, a number of descending interneurons have been described that may be involved in this reach-to-grasp behavior. One of these is the contralateral ON-type velocity-sensitive neuron (cONv). cONv was found to encode antennal joint-angle velocity during passive movement. Here, we characterize the transient response properties of cONv, including its dependence on joint angle range and direction. Since antennal hair field afferent terminals were shown to arborize close to cONv dendrites, we test whether antennal hair fields contribute to the joint-angle velocity encoding of cONv. To do so, we conducted bilateral extracellular recordings of both cONv interneurons per animal before and after hair field ablations. Our results show that cONv responses are highly transient, with velocity-dependent differences in delay and response magnitude. As yet, the steady state activity level was maintained until the stop of antennal movement, irrespective of movement velocity. Hair field ablation caused a moderate but significant reduction of movement-induced cONv firing rate by up to 40 %. We conclude that antennal proprioceptive hair fields contribute to the velocity-tuning of cONv, though further antennal mechanoreceptors must be involved, too.

Characterisation of multilayer materials using a position-sensitive atom probe

1990 ◽  
Vol 48 (4) ◽  
pp. 624-625
Author(s):  
RAD Mackenzie ◽  
G D W Smith ◽  
A. Cerezo ◽  
J A Liddle ◽  
CRM Grovenor ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Spatial Information ◽  
Chemical Vapour ◽  
Atom Probe ◽  
Organic Chemical ◽  
Growth Stages ◽  
Multiple Quantum ◽  
Quartz Wool ◽  
Position Sensitive

The position sensitive atom probe (POSAP), described briefly elsewhere in these proceedings, permits both chemical and spatial information in three dimensions to be recorded from a small volume of material. This technique is particularly applicable to situations where there are fine scale variations in composition present in the material under investigation. We report the application of the POSAP to the characterisation of semiconductor multiple quantum wells and metallic multilayers.The application of devices prepared from quantum well materials depends on the ability to accurately control both the quantum well composition and the quality of the interfaces between the well and barrier layers. A series of metal organic chemical vapour deposition (MOCVD) grown GaInAs-InP quantum wells were examined after being prepared under three different growth conditions. These samples were observed using the POSAP in order to study both the composition of the wells and the interface morphology. The first set of wells examined were prepared in a conventional reactor to which a quartz wool baffle had been added to promote gas intermixing. The effect of this was to hold a volume of gas within the chamber between growth stages, leading to a structure where the wells had a composition of GalnAsP lattice matched to the InP barriers, and where the interfaces were very indistinct. A POSAP image showing a well in this sample is shown in figure 1. The second set of wells were grown in the same reactor but with the quartz wool baffle removed. This set of wells were much better defined, as can be seen in figure 2, and the wells were much closer to the intended composition, but still with measurable levels of phosphorus. The final set of wells examined were prepared in a reactor where the design had the effect of minimizing the recirculating volume of gas. In this case there was again further improvement in the well quality. It also appears that the left hand side of the well in figure 2 is more abrupt than the right hand side, indicating that the switchover at this interface from barrier to well growth is more abrupt than the switchover at the other interface.

scholarly journals Action selection based on multiple-stimulus aspects in the wind-elicited escape behavior of crickets

2021 ◽  
Author(s):  
Nodoka Sato ◽  
Hisashi Shidara ◽  
Hiroto Ogawa
Keyword(s):  
Escape Behavior ◽  
Movement Direction ◽  
Neural Basis ◽  
Stimulus Velocity ◽  
Sensory Stimuli ◽  
Defensive Behaviors ◽  
Multiple Stimulus ◽  
Stimulus Parameters ◽  
Direction Control ◽  
Escape Responses

ABSTRACTAnimals detect approaching predators via sensory inputs through various modalities and immediately show an appropriate behavioral response to survive. Escape behavior is essential to avoid the predator’s attack and is more frequently observed than other defensive behaviors. In some species, multiple escape responses are exhibited with different movements. It has been reported that the approaching speed of a predator is important in choosing which escape action to take among the multiple responses. However, it is unknown whether other aspects of sensory stimuli, that indicate the predator’s approach, affect the selection of escape responses. We focused on two distinct escape responses (running and jumping) to a stimulus (short airflow) in crickets and examined the effects of multiple stimulus aspects (including the angle, velocity, and duration) on the choice between these escape responses. We found that the faster and longer the airflow, the more frequently the crickets jumped, meaning that they could choose their escape response depending on both velocity and duration of the stimulus. This result suggests that the neural basis for choosing escape responses includes the integration process of multiple stimulus parameters. It was also found that the moving speed and distance changed depending on the stimulus velocity and duration during running but not during jumping, suggesting higher adaptability of the running escape. In contrast, the movement direction was accurately controlled regardless of the stimulus parameters in both responses. The escape direction depended only on stimulus orientation, but not on velocity and duration.Summary statementWhen air currents triggering escape are faster and longer, crickets more frequently jump than run. Running speed and distance depend on stimulus velocity and duration, but direction control is independent.

Lesions of the Vestibular System Disrupt Hippocampal Theta Rhythm in the Rat

2006 ◽  
Vol 96 (1) ◽  
pp. 4-14 ◽  
Author(s):  
Noah A. Russell ◽  
Arata Horii ◽  
Paul F. Smith ◽  
Cynthia L. Darlington ◽  
David K. Bilkey
Keyword(s):  
Vestibular System ◽  
Hippocampal Neurons ◽  
Theta Rhythm ◽  
Spatial Information ◽  
Power Spectral Analysis ◽  
Spatial Location ◽  
Lesion Group ◽  
Movement Velocity ◽  
Ca1 Neurons ◽  
Ca1 Region

The hippocampus has a major role in memory for spatial location. Theta is a rhythmic hippocampal EEG oscillation that occurs at ∼8 Hz during voluntary movement and that may have some role in encoding spatial information. We investigated whether, as part of this process, theta might be influenced by self-movement signals provided by the vestibular system. The effects of bilateral peripheral vestibular lesions, made ≥60 days prior to recording, were assessed in freely moving rats. Power spectral analysis revealed that theta in the lesioned animals had a lower power and frequency compared with that recorded in the control animals. When the electroencephalography (EEG) was compared in epochs matched for speed of movement and acceleration, theta was less rhythmic in the lesioned group, indicating that the effect was not a result of between-group differences in this behavior. Blood measurements of corticosterone were also similar in the two groups indicating that the results could not be attributed to changes in stress levels. Despite the changes in theta EEG, individual neurons in the CA1 region of lesioned animals continued to fire with a periodicity of ∼8 Hz. The positive correlation between cell firing rate and movement velocity that is observed in CA1 neurons of normal animals was also maintained in cells recorded from lesion group animals. These findings indicate that although vestibular signals may contribute to theta rhythm generation, velocity-related firing in hippocampal neurons is dependent on nonvestibular signals such as sensory flow, proprioception, or motor efference copy.

Different planning policies for the initial movement velocity depending on whether the known uncertainty is in the cursor or in the target: Motor planning in situations where two potential movement distances exist

2021 ◽  
Author(s):  
Ryoji Onagawa ◽  
Kazutoshi Kudo ◽  
Kae Mukai
Keyword(s):  
Control Variable ◽  
Motor Planning ◽  
Movement Direction ◽  
Target Condition ◽  
Average Output ◽  
Movement Velocity ◽  
Directed Movement ◽  
Target Uncertainty ◽  
Starting Position ◽  
Initial Movement

During goal-directed behaviors, individuals are required to start a movement before deciding on the final goal. Previous studies have focused on the initial movement direction in situations involving multiple targets in different directions from the starting position and have shown that the movement is initiated in the average direction among the target directions. However, the previous studies only included situations with targets at equivalent distances, and the characteristics of motor planning in situations with multiple movement possibilities over different potential distances are unclear. In such situations, movement velocity is another important control variable. Furthermore, while previous studies examined situations with an uncertain motor target, uncertainty can also exist in the effector (e.g., body or tool locations). Therefore, we examined (1) whether the average output is confirmed in the initial movement velocity during execution in situations involving two potential movements with different distances. In addition, we examined (2) whether planning of the movement velocity can differ depending on the presence of uncertainty in the cursor or the target. In the main conditions, the participants were required to start a reaching movement with two potential movement distances; in the two-cursor condition, two cursors were presented before the start of the trial, and in the two-target condition, two targets were presented. As a control condition, a distance condition corresponding to each main condition was also performed. In the control condition, the initial movement velocity varied linearly with distance. Then, we tested whether the initial movement velocity in situations with two potential movement distances would follow the averaging output of the corresponding control condition. The results revealed that while the initial movement velocity in the two-target condition was slower than the averaging output, that in the two-cursor condition approached the averaging output. These results suggest that the velocity profile of the goal-directed movement is not simply averaged in a situation where two potential targets exist, and that there is a difference in the planning policy of the initial movement depending on whether the known uncertainty is for the movement goal or the effector.

Toward a living soft microrobot through optogenetic locomotion control of Caenorhabditis elegans

2021 ◽  
Vol 6 (55) ◽  
pp. eabe3950 ◽  
Author(s):  
Xianke Dong ◽  
Sina Kheiri ◽  
Yangning Lu ◽  
Zhaoyi Xu ◽  
Mei Zhen ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Phase Difference ◽  
High Performance ◽  
Nematode Species ◽  
Movement Direction ◽  
Neural Basis ◽  
Seamless Integration ◽  
C Elegans ◽  
Worm Body ◽  
Living Tissues

Learning from the locomotion of natural organisms is one of the most effective strategies for designing microrobots. However, the development of bioinspired microrobots is still challenging because of technical bottlenecks such as design and seamless integration of high-performance actuation mechanism and high-density energy source for untethered locomotion. Directly harnessing the activation energy and intelligence of living tissues in synthetic micromachines provides an alternative route to developing biohybrid microrobots. Here, we propose an approach to engineering the genetic and nervous systems of a nematode worm, Caenorhabditis elegans, and creating an untethered, highly controllable living soft microrobot (called “RoboWorm”). A living worm is engineered through optogenetic and biochemical methods to shut down the signal transmissions between its neuronal and muscular systems while its muscle cells still remain optically excitable. Through dynamic modeling and experimental verification of the worm crawling, we found that the phase difference between the worm body curvature and the muscular activation pattern generates the thrust force for crawling locomotion. By reproducing the phase difference via optogenetic excitation of the worm body muscles, we emulated the major worm crawling behaviors in a controllable manner. Furthermore, with real-time visual feedback of the worm crawling, we realized closed-loop regulation of the movement direction and destination of single worms. This technology may facilitate scientific studies on the biophysics and neural basis of crawling locomotion of C. elegans and other nematode species.

scholarly journals Principal components of hand kinematics and neurophysiological signals in motor cortex during reach to grasp movements

2014 ◽  
Vol 112 (8) ◽  
pp. 1857-1870 ◽  
Author(s):  
Mohsen Mollazadeh ◽  
Vikram Aggarwal ◽  
Nitish V. Thakor ◽  
Marc H. Schieber
Keyword(s):  
Motor Cortex ◽  
Joint Angle ◽  
Principal Component ◽  
Field Potentials ◽  
Joint Angles ◽  
Reach To Grasp ◽  
Lower Accuracy ◽  
Neurophysiological Data ◽  
Kinematic Synergies ◽  
Cross Correlations

A few kinematic synergies identified by principal component analysis (PCA) account for most of the variance in the coordinated joint rotations of the fingers and wrist used for a wide variety of hand movements. To examine the possibility that motor cortex might control the hand through such synergies, we collected simultaneous kinematic and neurophysiological data from monkeys performing a reach-to-grasp task. We used PCA, jPCA and isomap to extract kinematic synergies from 18 joint angles in the fingers and wrist and analyzed the relationships of both single-unit and multiunit spike recordings, as well as local field potentials (LFPs), to these synergies. For most spike recordings, the maximal absolute cross-correlations of firing rates were somewhat stronger with an individual joint angle than with any principal component (PC), any jPC or any isomap dimension. In decoding analyses, where spikes and LFP power in the 100- to 170-Hz band each provided better decoding than other LFP-based signals, the first PC was decoded as well as the best decoded joint angle. But the remaining PCs and jPCs were predicted with lower accuracy than individual joint angles. Although PCs, jPCs or isomap dimensions might provide a more parsimonious description of kinematics, our findings indicate that the kinematic synergies identified with these techniques are not represented in motor cortex more strongly than the original joint angles. We suggest that the motor cortex might act to sculpt the synergies generated by subcortical centers, superimposing an ability to individuate finger movements and adapt the hand to grasp a wide variety of objects.

scholarly journals Does Joint-angle Specificity After Short-term Isometric Strength Training Have A Neural Basis?

2018 ◽  
Vol 50 (5S) ◽  
pp. 51
Author(s):  
Marcel B. Lanza ◽  
Thomas G. Balshaw ◽  
Roxanas Panagiotis ◽  
Jonathan P. Folland
Keyword(s):  
Strength Training ◽  
Joint Angle ◽  
Isometric Strength ◽  
Neural Basis ◽  
Short Term

Jaw muscle afferent firing during an isotonic jaw-positioning task in the monkey

1983 ◽  
Vol 50 (1) ◽  
pp. 61-73 ◽  
Author(s):  
C. R. Larson ◽  
D. V. Finocchio ◽  
A. Smith ◽  
E. S. Luschei
Keyword(s):  
Firing Rate ◽  
Interspike Interval ◽  
Movement Velocity ◽  
Firing Rates ◽  
Actual Increase ◽  
Position Sensitivity ◽  
Jaw Muscle ◽  
Muscle Afferent ◽  
Position Sensitive ◽  
Jaw Position

The activity of jaw muscle receptors was studied by recording neurons in the mesencephalic nucleus of the trigeminal nerve in monkeys trained to control the position and movement of their mandible. Jaw position was measured by a weighted lever resting on the mandibular incisors. The force required to maintain the position of the lever was varied; in most cases it was either 25 or 360 g. Firing rates of neurons were related to stationary mandibular positions and to the velocity of movements during intervals when the movement velocity was constant. Of 49 neurons studied in detail, 21 fired at rates that were consistently and linearly related to static incisal openings. This static position sensitivity was typically about 5 spikes/mm of incisal opening. Most position-sensitive neurons fired at higher rates during opening movements and at lower rates during closing movements than would be accounted for by their position sensitivity. This sensitivity to the velocity of movement was not linear, however; slow closing movements sometimes did not produce a decrease in firing rate, and an actual increase during muscle shortening was seen in a few instances. The position sensitivity of eight neurons was evaluated during different loading conditions; in no case did it change substantially. Of the remaining 28 neurons, 26 fired at high rates during all opening movements and either stopped firing or fired at low, sporadic rates during closing movements. The static position sensitivity of these neurons was weak and variable both within and between neurons. The velocity sensitivity of these stretch-sensitive neurons was very nonlinear. Except for a range of slow movements (+/- 5 mm/s), the firing rate was maximal (200 spikes/s or higher) for most opening movements and zero for most closing movements. Maximal firing rates were higher when the loads being moved were increased from 25 to 360 g. The majority of position-sensitive neurons exhibited a large interspike-interval variability at wide incisal opening. In most of these neurons, this interspike-interval variability was periodic, usually at a rate of about 10 periods/s, and took the form of "saw-tooth" modulation on a record of instantaneous firing rate. Neurons that exhibited this modulation in a very prominent form also exhibited, in many instances, a substantial increase in firing rate during closing jaw movements.

Factors Controlling the Distribution and Fate of Nitrate in the Unsaturated Zone and Groundwater in a Semiarid Agriculture Area

2012 ◽  
Vol 518-523 ◽  
pp. 4892-4895
Author(s):  
Su Fen Wang ◽  
Tian Ming Huang ◽  
Ji Lai Liu ◽  
Yu Long Liu
Keyword(s):  
Soil Moisture ◽  
Water Table ◽  
Unsaturated Zone ◽  
Water Quality Management ◽  
Nitrate Pollution ◽  
Movement Direction ◽  
Nitrate Content ◽  
Movement Velocity ◽  
Moisture Movement ◽  
Pollute Groundwater

Overuse of fertilizers in agriculture could cause groundwater nitrate pollution. However, this is related to nitrate input, soil moisture movement (direction and rate), and depth of water table in (semi)arid areas, where nitrate can be preserved and nitrate loss by denitrification can be limited. A 18-m soil profile to water table in Daxing, Beijing shows that the nitrate is accumulated in the upper unsaturated zone and has not reached water table; and then groundwater nitrate remains at baseline level (5.6 mg/L). The soil moisture movement velocity is 0.28 m/yr based on nitrate use history. It takes another ~35 years for the moisture with high nitrate content to reach water table and pollute groundwater, to which attention should be paid in water quality management.

Sign in / Sign up

Export Citation Format

Share Document