scholarly journals Mechanisms of Coupling Between the Ipsilateral Legs of a Walking Insect (Carausius Morosus)

1988 ◽  
Vol 138 (1) ◽  
pp. 455-469 ◽  
Author(s):  
H. CRUSE ◽  
W. SCHWARZE
Keyword(s):  
Thin Film ◽  
Horizontal Plane ◽  
Silicone Oil ◽  
Stick Insect ◽  
Power Stroke ◽  
Carausius Morosus ◽  
Mechanical Coupling ◽  
Short Time ◽  
Coupling Mechanisms

The mechanisms by which the legs of a stick insect influence one another during walking were investigated by running the animals on a horizontal plane covered with a thin film of silicone oil to prevent mechanical coupling between the legs. Coupling between ipsilateral legs was investigated by interrupting the retraction (power stroke) of a leg for a short time and observing how the legs return to normal coordination following this disturbance. The results show that three ipsilateral coupling mechanisms exist: (a) a forwarddirected influence that inhibits the start of a protraction of the leg as long as the posterior leg is performing a protraction; (b) a forward-directed influence that excites the start of a protraction of the leg when the posterior leg starts a retraction movement; (c) a backward-directed influence that excites the start of a protraction, the influence being stronger the further the anterior leg has moved backwards during its retraction. The latter influence depends on the position but not the phase of the anterior leg.

scholarly journals Coupling Mechanisms Between the Contralateral Legs of a Walking Insect (Carausius Morosus)

1989 ◽  
Vol 144 (1) ◽  
pp. 199-213 ◽  
Author(s):  
H. CRUSE ◽  
A. KNAUTH
Keyword(s):  
Thin Film ◽  
Horizontal Plane ◽  
Silicone Oil ◽  
The Other ◽  
Carausius Morosus ◽  
Mechanical Coupling ◽  
Stick Insects ◽  
Coupling Mechanisms

Interactions between contralateral legs of stick insects during walking were examined in the absence of mechanical coupling between the legs by studying animals walking on a horizontal plane covered with a thin film of silicone oil. Investigations of undisturbed walks showed that contralateral coupling is weaker han ipsilateral coupling. Two types of influence were found, (i) For each pair of front, middle and rear legs, when one leg started a retraction movement, the probability for the contralateral leg to start a protraction was increased, (ii) For front- and hind-leg pairs, it was found that the probability of starting a protraction in one leg was also increased, the farther the other leg was moved backwards during retraction. Whether such influences exist between middle legs could not be determined. Both ‘excitatory’ mechanisms very much resemble those influences which have been found to exist between ipsilateral legs. However, in contrast to ipsilateral legs, the interaction between two contralateral legs was found to act in both directions.

scholarly journals Control of Stepping Velocity in the Stick Insect Carausius morosus

2009 ◽  
Vol 102 (2) ◽  
pp. 1180-1192 ◽  
Author(s):  
Matthias Gruhn ◽  
Géraldine von Uckermann ◽  
Sandra Westmark ◽  
Anne Wosnitza ◽  
Ansgar Büschges ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Walking Speed ◽  
Stick Insect ◽  
Behavioral Experiments ◽  
General Increase ◽  
Carausius Morosus ◽  
Mechanical Coupling ◽  
Stick Insects ◽  
Motoneuron Activity ◽  
Slippery Surface

We performed electrophysiological and behavioral experiments in single-leg preparations and intact animals of the stick insect Carausius morosus to understand mechanisms underlying the control of walking speed. At the level of the single leg, we found no significant correlation between stepping velocity and spike frequency of motor neurons (MNs) other than the previously shown modification in flexor (stance) MN activity. However, pauses between stance and swing motoneuron activity at the transition from stance to swing phase and stepping velocity are correlated. Pauses become shorter with increasing speed and completely disappear during fast stepping sequences. By means of extra- and intracellular recordings in single-leg stick insect preparations we found no systematic relationship between the velocity of a stepping front leg and the motoneuronal activity in the ipsi- or contralateral mesothoracic protractor and retractor, as well as flexor and extensor MNs. The observations on the lack of coordination of stepping velocity between legs in single-leg preparations were confirmed in behavioral experiments with intact stick insects tethered above a slippery surface, thereby effectively removing mechanical coupling through the ground. In this situation, there were again no systematic correlations between the stepping velocities of different legs, despite the finding that an increase in stepping velocity in a single front leg is correlated with a general increase in nerve activity in all connectives between the subesophageal and all thoracic ganglia. However, when the tethered animal increased walking speed due to a short tactile stimulus, provoking an escape-like response, stepping velocities of ipsilateral legs were found to be correlated for several steps. These results indicate that there is no permanent coordination of stepping velocities between legs, but that such coordination can be activated under certain circumstances.

scholarly journals Influence of Coxa-Thorax Joint Receptors on Retractor Motor Output During Walking in Carausius Morosus

1985 ◽  
Vol 114 (1) ◽  
pp. 131-139
Author(s):  
D. Graham
Keyword(s):  
Motor Activity ◽  
Stick Insect ◽  
Motor Output ◽  
Power Stroke ◽  
Retractor Muscle ◽  
Relative Timing ◽  
Forward Movement ◽  
Carausius Morosus ◽  
Joint Receptors ◽  
Weak Resistance

The coxal leg-stump of a stick insect was rotated about the coxa-thorax joint, by means of a pen-motor, while the animal walked on a self-propelled double treadwheel. Motor activity in the retractor muscles of the legs was recorded for standing and walking animals with the stump of either the middle or hind leg moved forward and backward in a trajectory similar to that used in a walking step. In a standing animal the movement of either leg evokes a weak resistance reflex. If the animal walks with the middle leg-stump held still, then short and weak motor bursts are generated with the periodicity of the walking legs. Front and hind legs alternate in a manner typical of the middle leg amputee and the retractor muscle of the amputated leg is most active during the power stroke of the leg behind. When a middle leg-stump is moved at a different frequency from that of the walking legs, the motor output to the retractor is strongly modulated and depends on the relative timing of the stump and the walking legs. Rearward movement of the hind leg-stump, during walking, is always accompanied by strong motor output in the retractor muscle. In addition, forward movement in this leg-stump produces a resistance reflex similar to that produced in the standing animal.

scholarly journals Two Coupling Mechanisms which determine the Coordination of Ipsilateral Legs in the Walking Crayfish

1986 ◽  
Vol 121 (1) ◽  
pp. 349-369 ◽  
Author(s):  
HOLK CRUSE ◽  
U. W. E. MÜLLER
Keyword(s):  
Model Calculation ◽  
Response Curve ◽  
Stance Phase ◽  
Phase Response Curve ◽  
Phase Response ◽  
Power Stroke ◽  
Return Stroke ◽  
Necessary And Sufficient ◽  
Short Time ◽  
Coupling Mechanisms

In a crayfish walking on a motor-driven belt at constant speed, the power stroke (stance phase) of an individual leg is experimentally prolonged for a short time; the ways the legs retain their normal coordination are then observed. The results are shown in a modified phase-response curve. Only ipsilateral coupling is considered in detail. Two coordinating mechanisms are necessary and sufficient to describe the experimental results. (1) The forward-directed influence is only active when the controlling (posterior) leg performs a power stroke. If the controlled leg is in power stroke, this influence leads it to interrupt the power stroke and start a return stroke. If the leg is in return stroke, it is influenced to continue the return stroke, the duration of which is thereby prolonged. The speed of the return stroke is also decreased. (2) The backward-directed influence is active only during the last part of the power stroke and the first part of the return stroke of the controlling (forward) leg. If the controlled leg is in return stroke, it is influenced to interrupt the return stroke and start a power stroke. If it is at the end of its power stroke, it is influenced to continue this stroke. For legs 3 and 4, each of which possesses both anterior and posterior neighbours, the influences exerted by these two coordinating mechanisms are assumed to be additive. A model calculation shows that the two mechanisms are sufficient to describe the behaviour observed. The results are compared with previous findings from the literature.

Characteristics and Potential Application of Thermally Sprayed Thin Film Coatings

2000 ◽  
Author(s):  
M. Loch ◽  
G. Barbezat
Keyword(s):  
Thin Film ◽  
New Technology ◽  
Functional Coatings ◽  
Oxide Coatings ◽  
Film Coatings ◽  
Thin Film Coatings ◽  
Thermally Sprayed Coatings ◽  
Short Time ◽  
Thermally Sprayed ◽  
Sprayed Coatings

Abstract LPPS Thin Film is a new technology for the production of thin functional coatings. The coatings produced can fill the well known gap of coating thickness between conventional thin films (PVD, CVD and others) and conventional thermally sprayed coatings (Plasma, HVOF and others). The application is successful, if the advantages of the new technology (large areas can be dense coated within a very short time) are combined with the specific properties of thermally sprayed coatings to the benefit of the intended application. Beside the technology of LPPS Thin Film and it's characteristics the paper will summarise important properties of Alumina described in the literature and present some corresponding properties of Aluminium oxide coatings produced by LPPS Thin Film.

Sex chromosomes and origin of males and sex mosaics of the parthenogenetic stick insect Carausius morosus Br.

Chromosoma ◽  
1980 ◽  
Vol 79 (1) ◽  
pp. 105-114 ◽  
Author(s):  
Laas P. Pijnacker ◽  
Margriet A. Ferwerda
Keyword(s):  
Sex Chromosomes ◽  
Stick Insect ◽  
Carausius Morosus

Hormonal Control of the Malpighian Tubules of the Stick Insect, Carausius Morosus

1970 ◽  
Vol 52 (3) ◽  
pp. 653-665 ◽  
Author(s):  
DIANA E. M. PILCHER
Keyword(s):  
Stick Insect ◽  
Hormonal Control ◽  
The State ◽  
Malpighian Tubules ◽  
Suboesophageal Ganglion ◽  
Carausius Morosus ◽  
Corpora Cardiaca ◽  
Diuretic Hormone ◽  
The Brain

1. Urine secretion by isolated Malpighian tubules of Carausius is accelerated by a diuretic hormone which can be extracted from the brain, corpora cardiaca and suboesophageal ganglion. 2. The level of this hormone in the haemolymph varies according to the state of hydration of the insect. 3. The hormone is inactivated by the tubules, and a mechanism is proposed whereby the tubules might be controlled by the hormone in vivo.

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