scholarly journals Thermal reception in the Mexican Lance-head rattlesnake, Crotalus polystictus

2018 ◽  
Author(s):  
Octavio I Martínez Vaca-León ◽  
Javier Manjarrez
Keyword(s):  
Behavioral Response ◽  
Head Movements ◽  
Head Orientation ◽  
Thermal Thresholds ◽  
Interspecific Differences ◽  
Neurophysiological Mechanisms ◽  
Thermal Detection ◽  
Tongue Flicks ◽  
Thermal Stimuli ◽  
Stimulus Shape

The sensory systems of Boidae and Crotalinae snakes detect subtle differences of thermal infrared energy. The complexity of this ability involves neurophysiological mechanisms with interspecific differences in the anatomy of thermoreceptor organs and functionally in thermal detection ranges and thermal thresholds, with ecological correlations that influence the thermo-reception. However, little is known about the information these snakes obtain and use from infrared radiation. We analyzed the behavioral response of adult Mexican Lance-head Rattlesnakes (Crotalus polystictus) to static thermal stimuli, evaluating the influence of distance from the snake of the thermal stimuli, and its lizard-like or mouse-like shape. The results reveal that C. polystictus is able to detect static thermal stimuli located from 20 to 200 cm away. Head movements and tongue-flicks were the most frequently performed behaviors, which suggests they are behaviors that can facilitate the detection of subtle differences in temperature of static stimuli. In addition, we suggest that stimulus shape and temperature are important in the timing of head orientation and frequency of tongue-flicks. We discuss the possible methodological and sensory implications of this behavioral response in C. polystictus.

scholarly journals Thermal reception in the Mexican Lance-head rattlesnake, Crotalus polystictus

2018 ◽  
Author(s):  
Octavio I Martínez Vaca-León ◽  
Javier Manjarrez
Keyword(s):  
Behavioral Response ◽  
Head Movements ◽  
Head Orientation ◽  
Thermal Thresholds ◽  
Interspecific Differences ◽  
Neurophysiological Mechanisms ◽  
Thermal Detection ◽  
Tongue Flicks ◽  
Thermal Stimuli ◽  
Stimulus Shape

The sensory systems of Boidae and Crotalinae snakes detect subtle differences of thermal infrared energy. The complexity of this ability involves neurophysiological mechanisms with interspecific differences in the anatomy of thermoreceptor organs and functionally in thermal detection ranges and thermal thresholds, with ecological correlations that influence the thermo-reception. However, little is known about the information these snakes obtain and use from infrared radiation. We analyzed the behavioral response of adult Mexican Lance-head Rattlesnakes (Crotalus polystictus) to static thermal stimuli, evaluating the influence of distance from the snake of the thermal stimuli, and its lizard-like or mouse-like shape. The results reveal that C. polystictus is able to detect static thermal stimuli located from 20 to 200 cm away. Head movements and tongue-flicks were the most frequently performed behaviors, which suggests they are behaviors that can facilitate the detection of subtle differences in temperature of static stimuli. In addition, we suggest that stimulus shape and temperature are important in the timing of head orientation and frequency of tongue-flicks. We discuss the possible methodological and sensory implications of this behavioral response in C. polystictus.

scholarly journals COMPARATIVE MEASUREMENTS OF HEAD ANGULAR MOVEMENTS USING A CAMERA SYSTEM AND A GYROSCOPE SYSTEM

2014 ◽  
Vol 54 (4) ◽  
pp. 295-300 ◽  
Author(s):  
Vladimir Socha ◽  
Patrik Kutilek ◽  
Ondrej Cakrt ◽  
Rudolf Cerny
Keyword(s):  
Head Movements ◽  
Head Orientation ◽  
Quiet Stance ◽  
Body Segment ◽  
Mean Velocity ◽  
Camera System ◽  
Rehabilitation Process ◽  
Gyroscope System ◽  
The Mean ◽  
2D Data

Assessments of body-segment angular movements are very important in the rehabilitation process. Head angular movements are measured and analyzed for use in studies of stability and posture. However, there is no methodology for assessing angular movements of the head, and it has not been verified whether data measured by fundamentally different MoCap systems will lead to the same results. In this study, we used a camera system and a 3DOF orientation tracker placed on the subject’s head, and measured inclination (roll) and flexion (pitch) during quiet stance. The total length and the mean velocity of the traces of the pitch versus roll plots were used to measure and analyze head orientation. Using these methods, we are able to model the distribution of the measured 2D data, and to evaluate stability and posture. The results show that the total lengths and the mean velocities related to the 3DOF orientation tracker do not differ significantly from the total lengths and the mean velocities of traces related to the IR medical camera. We also found that the systems are not interchangeable, and that the same type of system must be used each time. The designed methods can be used for studies not only of head movements but also of movements of other segments of the human body, and can be used to compare other types of MoCap systems, depending on the requirements for a specific rehabilitation examination.

scholarly journals Behavioral response of Caenorhabditis elegans to localized thermal stimuli

2013 ◽  
Vol 14 (1) ◽  
pp. 66 ◽  
Author(s):  
Aylia Mohammadi ◽  
Jarlath Byrne Rodgers ◽  
Ippei Kotera ◽  
William S Ryu
Keyword(s):  
Caenorhabditis Elegans ◽  
Behavioral Response ◽  
Thermal Stimuli

Cross-validated models of the relationships between neck muscle electromyography and three-dimensional head kinematics during gaze behavior

2012 ◽  
Vol 107 (2) ◽  
pp. 573-590 ◽  
Author(s):  
Farshad Farshadmanesh ◽  
Patrick Byrne ◽  
Gerald P. Keith ◽  
Hongying Wang ◽  
Brian D. Corneil ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Head Movements ◽  
Polynomial Model ◽  
Emg Activity ◽  
Head Orientation ◽  
Gaze Behavior ◽  
Data Set ◽  
Head Kinematics ◽  
Musculoskeletal Anatomy ◽  
Horizontal Head

The object of this study was to model the relationship between neck electromyography (EMG) and three-dimensional (3-D) head kinematics during gaze behavior. In two monkeys, we recorded 3-D gaze, head orientation, and bilateral EMG activity in the sternocleidomastoid, splenius capitis, complexus, biventer cervicis, rectus capitis posterior major, and occipital capitis inferior muscles. Head-unrestrained animals fixated and made gaze saccades between targets within a 60° × 60° grid. We performed a stepwise regression in which polynomial model terms were retained/rejected based on their tendency to increase/decrease a cross-validation-based measure of model generalizability. This revealed several results that could not have been predicted from knowledge of musculoskeletal anatomy. During head holding, EMG activity in most muscles was related to horizontal head orientation, whereas fewer muscles correlated to vertical head orientation and none to small random variations in head torsion. A fourth-order polynomial model, with horizontal head orientation as the only independent variable, generalized nearly as well as higher order models. For head movements, we added time-varying linear and nonlinear perturbations in velocity and acceleration to the previously derived static (head holding) models. The static models still explained most of the EMG variance, but the additional motion terms, which included horizontal, vertical, and torsional contributions, significantly improved the results. Several coordinate systems were used for both static and dynamic analyses, with Fick coordinates showing a marginal (nonsignificant) advantage. Thus, during gaze fixations, recruitment within the neck muscles from which we recorded contributed primarily to position-dependent horizontal orientation terms in our data set, with more complex multidimensional contributions emerging during the head movements that accompany gaze shifts. These are crucial components of the late neuromuscular transformations in a complete model of 3-D head-neck system and should help constrain the study of premotor signals for head control during gaze behaviors.

scholarly journals The signaling lipid sphingosine 1-phosphate regulates mechanical pain

2017 ◽  
Author(s):  
Rose Z. Hill ◽  
Benjamin U. Hoffman ◽  
Takeshi Morita ◽  
Stephanie M. Campos ◽  
Ellen A. Lumpkin ◽  
...  
Keyword(s):  
Behavioral Response ◽  
Neuronal Excitability ◽  
Mutant Mice ◽  
Mechanical Stimuli ◽  
Pain Thresholds ◽  
Somatosensory Neurons ◽  
Sphingosine 1 Phosphate ◽  
S1p Receptor ◽  
Mechanical Pain Thresholds ◽  
Thermal Stimuli

AbstractSomatosensory neurons mediate responses to diverse mechanical stimuli, from innocuous touch to noxious pain. While recent studies have identified distinct populations of A mechanonociceptors (AMs) that are required for mechanical pain, the molecular underpinnings of mechanonociception remain unknown. Here, we show that the bioactive lipid sphingosine 1-phosphate (S1P) and S1P Receptor 3 (S1PR3) are critical regulators of acute mechanonociception. Genetic or pharmacological ablation of S1PR3, or blockade of S1P production, significantly impaired the behavioral response to noxious mechanical stimuli, with no effect on responses to innocuous touch or thermal stimuli. These effects are mediated by fast-conducting A mechanonociceptors, which displayed a significant decrease in mechanosensitivity in S1PR3 mutant mice. We show that S1PR3 signaling tunes mechanonociceptor excitability via modulation of KCNQ2/3 channels. Our findings define a new role for S1PR3 in regulating neuronal excitability and establish the importance of S1P/S1PR3 signaling in the setting of mechanical pain thresholds.

scholarly journals The Critical Role of Head Movements for Spatial Representation During Bumblebees Learning Flight

2021 ◽  
Vol 14 ◽  
Author(s):  
Charlotte Doussot ◽  
Olivier J. N. Bertrand ◽  
Martin Egelhaaf
Keyword(s):  
Reference Frame ◽  
Apparent Motion ◽  
Visual Information ◽  
Reference Frames ◽  
Head Movements ◽  
Gaze Direction ◽  
Depth Information ◽  
Head Orientation ◽  
Pivot Point ◽  
The Gaze

Bumblebees perform complex flight maneuvers around the barely visible entrance of their nest upon their first departures. During these flights bees learn visual information about the surroundings, possibly including its spatial layout. They rely on this information to return home. Depth information can be derived from the apparent motion of the scenery on the bees' retina. This motion is shaped by the animal's flight and orientation: Bees employ a saccadic flight and gaze strategy, where rapid turns of the head (saccades) alternate with flight segments of apparently constant gaze direction (intersaccades). When during intersaccades the gaze direction is kept relatively constant, the apparent motion contains information about the distance of the animal to environmental objects, and thus, in an egocentric reference frame. Alternatively, when the gaze direction rotates around a fixed point in space, the animal perceives the depth structure relative to this pivot point, i.e., in an allocentric reference frame. If the pivot point is at the nest-hole, the information is nest-centric. Here, we investigate in which reference frames bumblebees perceive depth information during their learning flights. By precisely tracking the head orientation, we found that half of the time, the head appears to pivot actively. However, only few of the corresponding pivot points are close to the nest entrance. Our results indicate that bumblebees perceive visual information in several reference frames when they learn about the surroundings of a behaviorally relevant location.

scholarly journals 3D Dynamic Modeling of the Head-Neck Complex for Fast Eye and Head Orientation Movements Research

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Daniel A. Sierra ◽  
John D. Enderle
Keyword(s):  
Neural Control ◽  
Soft Tissues ◽  
Head Movements ◽  
Head Orientation ◽  
Facet Joints ◽  
Intervertebral Disks ◽  
Correct Information ◽  
Safety Research ◽  
Time Optimal ◽  
Head Neck

A 3D dynamic computer model for the movement of the head-neck complex is presented. It incorporates anatomically correct information about the diverse elements forming the system. The skeleton is considered as a set of interconnected rigid 3D bodies following the Newton-Euler laws of movement. The muscles are modeled using Enderle's linear model, which shows equivalent dynamic characteristics to Loeb's virtual muscle model. The soft tissues, namely, the ligaments, intervertebral disks, and facet joints, are modeled considering their physiological roles and dynamics. In contrast with other head and neck models developed for safety research, the model is aimed to study the neural control of the complex during fast eye and head movements, such as saccades and gaze shifts. In particular, the time-optimal hypothesis and the feedback control ones are discussed.

scholarly journals Spontaneous visual exploration during locomotion in patients with phobic postural vertigo

2020 ◽  
Vol 267 (S1) ◽  
pp. 223-230
Author(s):  
J. Penkava ◽  
S. Bardins ◽  
T. Brandt ◽  
M. Wuehr ◽  
D. Huppert
Keyword(s):  
Rating Scale ◽  
Numeric Rating Scale ◽  
Head Movements ◽  
Visual Exploration ◽  
Walking Distance ◽  
Head Orientation ◽  
Healthy Controls ◽  
Phobic Postural Vertigo ◽  
Exploration Behavior ◽  
Numeric Rating

Abstract Background Earlier studies on stance and gait with posturographic and EMG-recordings and automatic gait analysis in patients with phobic postural vertigo (PPV) or visual height intolerance (vHI) revealed similar patterns of body stiffening with muscle co-contraction and a slow, cautious gait. Visual exploration in vHI patients was characterized by a freezing of gaze-in-space when standing and reduced horizontal eye and head movements during locomotion. Objective Based on the findings in vHI patients, the current study was performed with a focus on visual control of locomotion in patients with PPV while walking along a crowded hospital hallway. Methods Twelve patients with PPV and eleven controls were recruited. Participants wore a mobile infrared video eye-tracking system that continuously measured eye-in-head movements in the horizontal and vertical planes and head orientation and motion in the yaw, pitch, and roll planes. Visual exploration behavior of participants was recorded at the individually preferred speed for a total walking distance of 200 m. Gaze-in-space directions were determined by combining eye-in-head and head-in-space orientation. Walking speeds were calculated based on the trial duration and the total distance traversed. Participants were asked to rate their feelings of discomfort during the walk on a 4-point numeric rating scale. The examiners rated the crowdedness of the hospital hallway on a 4-point numeric rating scale. Results The major results of visual exploration behavior in patients with PPV in comparison to healthy controls were: eye and head positions were directed more downward in the vertical plane towards the ground ahead with increased frequency of large amplitude vertical orientation movements towards the destination, the end of the ground straight ahead. The self-adjusted speed of locomotion was significantly lower in PPV. Particularly those patients that reported high levels of discomfort exhibited a specific visual exploration of their horizontal surroundings. The durations of fixating targets in the visual surroundings were significantly shorter as compared to controls. Conclusion Gaze control of locomotion in patients with PPV is characterized by a preferred deviation of gaze more downward and by horizontal explorations for suitable auxiliary means for potential postural support in order to prevent impending falls. These eye movements have shorter durations of fixation as compared to healthy controls and patients with vHI. Finally, the pathological alterations in eye–head coordination during locomotion correlate with a higher level of discomfort and anxiety about falling.

scholarly journals Utricular afferents: morphology of peripheral terminals

2015 ◽  
Vol 113 (7) ◽  
pp. 2420-2433 ◽  
Author(s):  
J. A. Huwe ◽  
G. J. Logan ◽  
B. Williams ◽  
M. H. Rowe ◽  
E. H. Peterson
Keyword(s):  
Head Movement ◽  
Calcium Binding ◽  
Three Dimensional ◽  
Small Diameter ◽  
Head Movements ◽  
Hair Bundle ◽  
Movement Direction ◽  
Head Orientation ◽  
Functional Roles ◽  
Bundle Structure

The utricle provides critical information about spatiotemporal properties of head movement. It comprises multiple subdivisions whose functional roles are poorly understood. We previously identified four subdivisions in turtle utricle, based on hair bundle structure and mechanics, otoconial membrane structure and hair bundle coupling, and immunoreactivity to calcium-binding proteins. Here we ask whether these macular subdivisions are innervated by distinctive populations of afferents to help us understand the role each subdivision plays in signaling head movements. We quantified the morphology of 173 afferents and identified six afferent classes, which differ in structure and macular locus. Calyceal and dimorphic afferents innervate one striolar band. Bouton afferents innervate a second striolar band; they have elongated terminals and the thickest processes and axons of all bouton units. Bouton afferents in lateral (LES) and medial (MES) extrastriolae have small-diameter axons but differ in collecting area, bouton number, and hair cell contacts (LES >> MES). A fourth, distinctive population of bouton afferents supplies the juxtastriola. These results, combined with our earlier findings on utricular hair cells and the otoconial membrane, suggest the hypotheses that MES and calyceal afferents encode head movement direction with high spatial resolution and that MES afferents are well suited to signal three-dimensional head orientation and striolar afferents to signal head movement onset.

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