scholarly journals Body side-specific changes in sensorimotor processing of movement feedback in a walking insect

2019 ◽  
Vol 122 (5) ◽  
pp. 2173-2186 ◽  
Author(s):  
Joscha Schmitz ◽  
Matthias Gruhn ◽  
Ansgar Büschges
Keyword(s):  
Stick Insect ◽  
The Body ◽  
Motor Output ◽  
Chordotonal Organ ◽  
Stimulus Velocity ◽  
Motor Processing ◽  
Sensorimotor Processing ◽  
Body Side ◽  
The Difference ◽  
Leg Kinematics

Feedback from load and movement sensors can modify timing and magnitude of the motor output in the stepping stick insect. One source of feedback is stretch reception by the femoral chordotonal organ (fCO), which encodes such parameters as the femorotibial (FTi) joint angle, the angular velocity, and its acceleration. Stimulation of the fCO causes a postural resistance reflex, during quiescence, and can elicit the opposite, so-called active reaction (AR), which assists ongoing flexion during active movements. In the present study, we investigated the role of fCO feedback for the difference in likelihood of generating ARs on the inside vs. the outside during curve stepping. We analyzed the effects of fCO stimulation on the motor output to the FTi and the neighboring coxa-trochanter and thorax-coxa joints of the middle leg. In inside and outside turns, the probability for ARs increases with increasing starting angle and decreasing stimulus velocity; furthermore, it is independent of the total angular excursion. However, the transition between stance and swing motor activity always occurs after a specific angular excursion, independent of the turning direction. Feedback from the fCO also has an excitatory influence on levator trochanteris motoneurons (MNs) during inside and outside turns, whereas the same feedback affects protractor coxae MNs only during outside steps. Our results suggest joint- and body side-dependent processing of fCO feedback. A shift in gain may be responsible for different AR probabilities between inside and outside turning, whereas the general control mechanism for ARs is unchanged. NEW & NOTEWORTHY We show that parameters of movement feedback from the tibia in an insect during curve walking are processed in a body side-specific manner, and how. From our results it is highly conceivable that the difference in motor response to the feedback supports the body side-specific leg kinematics during turning. Future studies will need to determine the source for the inputs that determine the local changes in sensory-motor processing.

Premotor Interneurons in the Local Control of Stepping Motor Output for the Stick Insect Single Middle Leg

2009 ◽  
Vol 102 (3) ◽  
pp. 1956-1975 ◽  
Author(s):  
Géraldine von Uckermann ◽  
Ansgar Büschges
Keyword(s):  
Stance Phase ◽  
Stick Insect ◽  
Motor Output ◽  
Chordotonal Organ ◽  
Locomotor System ◽  
State Dependent ◽  
Nonspiking Interneurons ◽  
Leg Kinematics ◽  
Control Regime

In insect walking systems, nonspiking interneurons (NSIs) play an important role in the control of posture and movement. As such NSIs are known to contribute to state-dependent modifications in processing of proprioceptive signals from the legs. For example, NSIs process a flexion of the femur-tibia (FTi) joint signaled by the femoral chordotonal organ (fCO) such that the stance phase motor output is reinforced in the active locomotor system. This phenomenon representing a reflex reversal is the first part of the “active reaction” (AR) and was hypothesized to functionally represent a major control feature by which sensory feedback supports stance generation. As NSIs are known to contribute to the AR, the question arises, whether they serve similar functions during stepping and whether the AR is generally part of the control system for walking. We studied these issues in vivo, in a single leg preparation of Carausius morosus with the leg kinematics being confined to changes in one plane, along the coxa-trochanteral and the FTi-joint. Following kinematic analysis, identified NSIs (E1-E8, I1, I2, and I4) were recorded intracellularly during single leg stepping at different velocities. We detected clear similarities between the activity pattern of NSIs during single leg stepping and their responses to fCO-stimulation during the generation of the AR. This strongly supports the notion that the motor output generated during the AR reflects part of the control regime for stepping. Furthermore, our experiments revealed that alterations in stepping velocity result from modifications in the activity of the premotor NSIs involved in stance phase generation.

Load Signals Assist the Generation of Movement-Dependent Reflex Reversal in the Femur–Tibia Joint of Stick Insects

2006 ◽  
Vol 96 (6) ◽  
pp. 3532-3537 ◽  
Author(s):  
Turgay Akay ◽  
Ansgar Büschges
Keyword(s):  
Time Course ◽  
Stick Insect ◽  
Motor Output ◽  
Chordotonal Organ ◽  
Frequency Of Occurrence ◽  
Stick Insects ◽  
Extensor Motoneuron ◽  
Motoneuron Activity ◽  
First Time ◽  
Stimulation Of

Reinforcement of movement is an important mechanism by which sensory feedback contributes to motor control for walking. We investigate how sensory signals from movement and load sensors interact in controlling the motor output of the stick insect femur–tibia (FT) joint. In stick insects, flexion signals from the femoral chordotonal organ (fCO) at the FT joint and load signals from the femoral campaniform sensilla (fCS) are known to individually reinforce stance-phase motor output of the FT joint by promoting flexor and inhibiting extensor motoneuron activity. We quantitatively compared the time course of inactivation in extensor tibiae motoneurons in response to selective stimulation of fCS and fCO. Stimulation of either sensor generates extensor activity in a qualitatively similar manner but with a significantly different time course and frequency of occurrence. Inactivation of extensor motoneurons arising from fCS stimulation was more reliable but more than threefold slower compared with the extensor inactivation in response to flexion signals from the fCO. In contrast, simultaneous stimulation of both sense organs produced inactivation in motoneurons with a time course typical for fCO stimulation alone, but with a frequency of occurrence characteristic for fCS stimulation. This increase in probability of occurrence was also accompanied by a delayed reactivation of the extensor motoneurons. Our results indicate for the first time that load signals from the leg affect the processing of movement-related feedback in controlling motor output.

scholarly journals Motor Output of the Denervated Thoracic Ventral Nerve Cord in the Stick Insect Carausius Morosus

1983 ◽  
Vol 105 (1) ◽  
pp. 127-145 ◽  
Author(s):  
ULRICH BÄSSLER ◽  
U. T. A. WEGNER
Keyword(s):  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Intact Animal ◽  
Stick Insect ◽  
Motor Output ◽  
The Other ◽  
Chordotonal Organ ◽  
Motor Neurones ◽  
Leg Movements ◽  
Stimulation Of

The denervated thoracic ventral nerve cord produces a motor output which is similar to that observed in the intact animal during irregular leg movements (seeking movements) or rocking, but not walking. When the nerves to some legs are left intact, and the animal walks on a wheel, the motor output in the protractor and retractor motor neurones of the denervated legs is modulated by the stepping frequency of the walking legs. The modulation is similar to that observed in the motor output to a not actually stepping leg of an intact walking animal. When only the crural nerve of one leg is left intact, stimulation of the trochanteral campaniform sensilli induces protractor and retractor motor output to that leg and the leg behind it. In this case the motor output to the ipsilateral leg is in phase. Stimulation of the femoral chordotonal organ influences activity in motor neurones of the extensor tibiae (FETi and SETi) but not those of the protractor and retractor coxae muscles. In a restrained leg of an intact animal stretching of the femoral chordotonal organ excites FETi and SETi as long as the other legs walk (as in a walking leg) and inhibits FETi and SETi (as in a seeking leg) when the other legs are unable to walk.

Nonspiking local interneurons in insect leg motor control. I. Common layout and species-specific response properties of femur-tibia joint control pathways in stick insect and locust

1995 ◽  
Vol 73 (5) ◽  
pp. 1843-1860 ◽  
Author(s):  
A. Buschges ◽  
H. Wolf
Keyword(s):  
Motor Control ◽  
Neuronal Networks ◽  
Stick Insect ◽  
Chordotonal Organ ◽  
Joint Control ◽  
Stimulus Velocity ◽  
Important Prerequisite ◽  
Local Interneurons ◽  
Stick Insects ◽  
Species Specific

1. Locusts (Locusta migratoria) and stick insects (Carausius morosus) exhibit different strategies for predator avoidance. Locusts rely primarily on walking and jumping to evade predators, whereas stick insects become cataleptic, catalepsy forming a major component of the twig mimesis exhibited by this species. The neuronal networks that control postural leg movements in locusts and stick insects are tuned differently to their specific behavioral tasks. An important prerequisite for the production of catalepsy in the stick insect is the marked velocity dependency of the control network, which appears to be generated at the level of nonspiking local interneurons. We examined interneuronal pathways in the network controlling the femur-tibia joint of the locust middle leg and compared its properties with those described for the stick insect middle leg. It was our aim to identify possible neural correlates of the species-specific behavior with regard to postural leg motor control. 2. We obtained evidence that the neuronal networks that control the femur-tibia joints in the two species consist of morphologically and physiologically similar--and thus probably homologous--interneurons. Qualitatively, these interneurons receive the same input from the femoral chordotonal organ receptors and they drive the same pools of leg motoneurons in both species. 3. Pathways that contribute to the control of the femur-tibia joint include interneurons that support both "resisting" and "assisting" responses with respect to the motoneuron activity that is actually elicited during reflex movements. Signal processing via parallel, antagonistic pathways therefore appears to be a common principle in insect leg motor control. 4. Differences between the two insect species were found with regard to the processing of velocity information provided by the femoral chordotonal organ. Interneuronal pathways are sensitive to stimulus velocity in both species. However, in the locust there is no marked velocity dependency of the interneuronal responses, whereas in the same interneurons of the stick insect it is pronounced. This characteristic was maintained at the level of the motoneurons controlling the femur-tibia joint. Pathways for postural leg motor control in the locust thus lack an important prerequisite for the generation of catalepsy, that is, a marked velocity dependency.

Our Bodies, Whose Property?

2013 ◽  
Author(s):  
Anne Phillips
Keyword(s):  
Labor Markets ◽  
Personal Autonomy ◽  
The Body ◽  
Body Parts ◽  
Complex Issue ◽  
Human Organs ◽  
Property Owners ◽  
The Common ◽  
The Difference ◽  
The Right

No one wants to be treated like an object, regarded as an item of property, or put up for sale. Yet many people frame personal autonomy in terms of self-ownership, representing themselves as property owners with the right to do as they wish with their bodies. Others do not use the language of property, but are similarly insistent on the rights of free individuals to decide for themselves whether to engage in commercial transactions for sex, reproduction, or organ sales. Drawing on analyses of rape, surrogacy, and markets in human organs, this book challenges notions of freedom based on ownership of our bodies and argues against the normalization of markets in bodily services and parts. The book explores the risks associated with metaphors of property and the reasons why the commodification of the body remains problematic. The book asks what is wrong with thinking of oneself as the owner of one's body? What is wrong with making our bodies available for rent or sale? What, if anything, is the difference between markets in sex, reproduction, or human body parts, and the other markets we commonly applaud? The book contends that body markets occupy the outer edges of a continuum that is, in some way, a feature of all labor markets. But it also emphasizes that we all have bodies, and considers the implications of this otherwise banal fact for equality. Bodies remind us of shared vulnerability, alerting us to the common experience of living as embodied beings in the same world. Examining the complex issue of body exceptionalism, the book demonstrates that treating the body as property makes human equality harder to comprehend.

Theory-Practice Gap: The Experiences of Nigerian Nursing Students

2018 ◽  
Vol 20 (1) ◽  
Author(s):  
Titilayo Dorothy Odetola ◽  
Olusola Oluwasola ◽  
Christoph Pimmer ◽  
Oluwafemi Dipeolu ◽  
Samson Oluwayemi Akande ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Nursing Students ◽  
Developing Country ◽  
The Body ◽  
Clinical Staff ◽  
Clinical Settings ◽  
Practice Gap ◽  
The Difference ◽  
Analyse Data ◽  
Theory Practice Gap

The “disconnect” between the body of knowledge acquired in classroom settings and the application of this knowledge in clinical practice is one of the main reasons for professional fear, anxiety and feelings of incompetence among freshly graduated nurses. While the phenomenon of the theory-to-practice gap has been researched quite extensively in high-income country settings much less is known about nursing students’ experiences in a developing country context. To rectify this shortcoming, the qualitative study investigated the experiences of nursing students in their attempt to apply what they learn in classrooms in clinical learning contexts in seven sites in Nigeria. Thematic content analysis was used to analyse data gained from eight focus group discussions (n = 80) with the students. The findings reveal a multifaceted theory-practice gap which plays out along four tensions: (1) procedural, i.e. the difference between practices from education institutions and the ones enacted in clinical wards – and contradictions that emerge even within one clinical setting; (2) political, i.e. conflicts that arise between students and clinical staff, especially personnel with a lower qualification profile than the degree that students pursue; (3) material, i.e. the disconnect between contemporary instruments and equipment available in schools and the lack thereof in clinical settings; and (4) temporal, i.e. restricted opportunities for supervised practice owing to time constraints in clinical settings in which education tends to be undervalued. Many of these aspects are linked to and aggravated by infrastructural limitations, which are typical for the setting of a developing country. Nursing students need to be prepared regarding how to deal with the identified procedural, political, material and temporal tensions before and while being immersed in clinical practice, and, in so doing, they need to be supported by educationally better qualified clinical staff.

Perbedaan Penggunaan Antikoagulan K2EDTA DAN K3EDTA Terhadap Hasil Pemeriksaan Indeks Eritrosit

2018 ◽  
Vol 1 (2) ◽  
pp. 114
Author(s):  
Wahdaniah Wahdaniah ◽  
Sri Tumpuk
Keyword(s):  
Screening Test ◽  
Venous Blood ◽  
The Body ◽  
Ethylene Diamine ◽  
P Value ◽  
Cross Sectional ◽  
Significant Difference ◽  
Ethylene Diamine Tetra Acetate ◽  
The Difference ◽  
Index Value

Abstract: Routine blood examination is the earliest blood test or screening test to determine the diagnosis of an abnormality. Blood easily froze if it is outside the body and can be prevented by the addition of anticoagulants, one of which Ethylene Diamine Tetra Acetate (EDTA). Currently available vacuum tubes containing EDTA anticoagulants in the form of K2EDTA and K3EDTA. K3EDTA is usually a salt that has better stability than other EDTA salts because it shows a pH approaching a blood pH of about 6.4. The purpose of this research is to know the difference of erythrocyte index results include MCH, MCV and MCHC using K3EDTA anticoagulant with K2EDTA. This research is a cross sectional design. This study used venous blood samples mixed with K2EDTA anticoagulant and venous blood mixed with K3EDTA anticoagulants, each of 30 samples. Data were collected and analyzed using paired different test. Based on data analysis that has been done on MCH examination, p value <0,05 then there is a significant difference between samples with K3EDTA anticoagulant with K2EDTA to erythrocyte index value. Then on the examination of MCV and MCHC obtained p value <0.05 then there is no significant difference between samples with K3EDTA anticoagulant with K2EDTA to erythrocyte index value.Abstrak: Pemeriksaan darah rutin merupakan pemeriksaan darah yang paling awal atau screening test untuk mengetahui diagnosis suatu kelainan. Darah mudah membeku jika berada diluar tubuh dan bisa dicegah dengan penambahan antikoagulan, salah satunya Ethylene Diamine Tetra Acetate (EDTA). Dewasa ini telah tersedia tabung vakum yang sudah berisi antikoagulan EDTA dalam bentuk  K2EDTA dan  K3EDTA. K3EDTA  biasanya berupa garam yang mempunyai stabilitas yang lebih baik dari garam EDTA yang lain karena menunjukkan pH yang mendekati pH darah yaitu sekitar 6,4. Tujuan dari penelitian ini adalah untuk mengetahui perbedaan hasil indeks eritrosit meliputi MCH, MCV dan MCHC menggunakan antikoagulan K3EDTA dengan K2EDTA. Penelitian ini merupakan penelitian dengan desain cross sectional. Penelitian ini menggunakan sampel darah vena yang dicampur dengan antikoagulan K2EDTA dan darah vena yang dicampur dengan antikoagulan K3EDTA, masing-masing sebanyak 30 sampel. Data dikumpulkan dan dianalisis menggunakan uji beda berpasangan. Berdasarkan analisis data yang telah dilakukan pada pemeriksaan MCH didapatkan nilai p < 0,05 maka ada perbedaan yang signifikan antara sampel dengan antikoagulan K3EDTA dengan K2EDTA terhadap nilai indeks eritrosit. Kemudian pada pemeriksaan MCV dan MCHC didapatkan nilai p < 0,05 maka tidak ada perbedaan yang signifikan antara sampel dengan antikoagulan K3EDTA dengan K2EDTA terhadap nilai indeks eritrosit.

Effect of Sample Storage Conditions on Body Burden Analysis of Organic Contaminants in Unionid Mussels

1992 ◽  
Vol 27 (4) ◽  
pp. 833-844 ◽  
Author(s):  
Micheline Hanna
Keyword(s):  
Organic Contaminants ◽  
Body Burden ◽  
Storage Conditions ◽  
The Body ◽  
Sample Storage ◽  
Pcb Congeners ◽  
Unionid Mussels ◽  
Group A ◽  
The Difference ◽  
Group B

Abstract In order to quantitatively assess the effect of sample storage conditions on the body burden analysis of organic contaminants, a comparative analysis was carried out on the unionid mussel Elliptic complanata. The mussels were divided into two groups, each with distinct storage conditions, while Group A was kept in the freezer at −20°C, Group B was kept in the refrigerator for five days at 5°C. All the compounds present in the control were also present in Group B samples. Analysis of the organic contaminants in each of these two groups showed that for total PCB concentrations, the two treatments were not significantly different; however when compared individually 6 of the 13 PCB congeners showed significant differences. The observed differences were relatively small for individual PCB congeners (7.1 to 15.3%), higher for chlorobenzenes (10.5 to 36.4%), and yet higher for HCE (44.1%); the difference for HCE, although large is nevertheless not significant, even if only marginally so.

scholarly journals The Respiration of some Planktonic copepods II. The Effect Of Temperature

1953 ◽  
Vol 31 (3) ◽  
pp. 447-460 ◽  
Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont
Keyword(s):  
Respiratory Rate ◽  
The Body ◽  
The Other ◽  
Effect Of Temperature ◽  
Acartia Clausi ◽  
Temora Longicornis ◽  
Different Temperatures ◽  
Planktonic Copepods ◽  
The Difference ◽  
The Relationship

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.

scholarly journals Changes in Children’s Body Composition and Posture during Puberty Growth

Children ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 288
Author(s):  
Wojciech Rusek ◽  
Joanna Baran ◽  
Justyna Leszczak ◽  
Marzena Adamczyk ◽  
Rafał Baran ◽  
...  
Keyword(s):  
Body Composition ◽  
Adipose Tissue ◽  
Regression Analysis ◽  
Body Mass ◽  
Pelvic Obliquity ◽  
The Body ◽  
Body Posture ◽  
Older Children ◽  
The Difference ◽  
The Right

The main goal of our study was to determine how the age of children, puberty and anthropometric parameters affect the formation of body composition and faulty body posture development in children. The secondary goal was to determine in which body segments abnormalities most often occur and how gender differentiates the occurrence of adverse changes in children’s body posture and body composition during puberty. The study group consisted of 464 schoolchildren aged from 6–16. Body posture was assessed with the Zebris system. The composition of the body mass was tested with Tanita MC 780 MA body mass analyzer and the body height was measured using a portable stadiometer PORTSTAND 210. The participants were further divided due to the age of puberty. Tanner division was adopted. The cut-off age for girls is ≥10 years and for boys it is ≥12 years. The analyses applied descriptive statistics, the Pearson correlation, stepwise regression analysis and the t-test. The accepted level of significance was p < 0.05. The pelvic obliquity was lower in older children (beta = −0.15). We also see that age played a significant role in the difference in the height of the right pelvis (beta = −0.28), and the difference in the height of the right shoulder (beta = 0.23). Regression analysis showed that the content of adipose tissue (FAT%) increased with body mass index (BMI) and decreased with increasing weight, age, and height. Moreover, the FAT% was lower in boys than in girls (beta negative equal to −0.39). It turned out that older children (puberty), had greater asymmetry in the right shoulder blade (p < 0.001) and right shoulder (p = 0.003). On the other hand, younger children (who were still before puberty) had greater anomalies in the left trunk inclination (p = 0.048) as well as in the pelvic obliquity (p = 0.008). Girls in puberty were characterized by greater asymmetry on the right side, including the shoulders (p = 0.001), the scapula (p = 0.001) and the pelvis (p < 0.001). In boys, the problem related only to the asymmetry of the shoulder blades (p < 0.001). Girls were characterized by a greater increase in adipose tissue and boys by muscle tissue. Significant differences also appeared in the body posture of the examined children. Greater asymmetry within scapulas and shoulders were seen in children during puberty. Therefore, a growing child should be closely monitored to protect them from the adverse consequences of poor posture or excessive accumulation of adipose tissue in the body.

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