Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Gain control in a proprioceptive feedback loop as a prerequisite for working close to instability (1994)
    Springer
    Journal of comparative physiology 175 (1994), S. 23-33 
    Details
    ISSN: 1432-1351
    Keywords: Gain control ; Stability of feedback control Stick insect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract In the artificially closed femur-tibia control system of stick insects oscillations were induced in 3 different ways: Increasing the phase-shift by introducing an electronic delay, afference sign reversal and coupling the tibia to an inert mass. In all 3 cases the oscillations stopped after some time. The gain of the open-loop system was significantly smaller after the oscillations. Afference sign reversal by surgically crossing of the receptor apodeme of the femoral chordotonal organ for 25–85 days does not lead to altered characteristics of the control loop. When sinusoidal passive movements are forced upon the intact femur-tibia joint the forces resisting these movements do not decrease with time. In contrast to direct stimulation of the femoral chordotonal organ, these passive movements also influence the contralateral leg. The experiments show that the gain-control system of the femur-tibia control loop of stick insects consists of at least two components: A sensitization system (with inputs from many kinds of stimuli indicating some kind of disturbance) increases the gain of all reflex loops. A specific habituation-like system decreases the gain with repetitive stimulation only of one control system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217433
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Information processing in the femur-tibia control loop of stick insects (1995)
    Springer
    Journal of comparative physiology 177 (1995), S. 145-158 
    Details
    ISSN: 1432-1351
    Keywords: Nonspiking interneuron ; Neuronal network ; Posture control ; Simulation ; Parliamentary principle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The complicated response characteristics of the identified nonspiking interneuron type E4 upon elongation stimuli to the femoral chordotonal organ (fCO) can be obtained by a computer simulation using the neuronal network simulator BioSim, if the following assumptions were introduced: (1) The interneurons receive direct excitatory input from position- and velocity-sensitive fCO afferents but also, in parallel delayed inhibition from the same velocity-sensitive afferents. (2) Position-sensitive afferents in part show adaptation with a rather long time-constant. A subsequent experimental analysis demonstrated that all these assumptions fit the reality: (1) Interneurons of type E4 receive direct excitatory input from fCO afferents. (2) Interneurons of type E4 are affected by velocity dependent delayed inhibitory inputs from the fCO. (3) The fCO does contain adapting position-sensitive sensory neurons, which have not been described before. The described principle of the information processing is also able to generate the response in interneurons of type E6 with less steep amplitude-velocity characteristic due to a different weighting of the direct excitation and delayed inhibition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225095
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Zur Bedeutung der Antennen für die Wahrnehmung der Schwerkraftrichtung bei der Stabheuschrecke Carausius morosus (1971)
    Springer
    Biological cybernetics 9 (1971), S. 31-34 
    Details
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Summary The result of the following presentation is that antennal receptors affect only the sign of the geotactic turning tendency, but not its amount.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00272558
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Timing and shaping influences on the motor output for walking in stick insects (1987)
    Springer
    Biological cybernetics 55 (1987), S. 397-401 
    Details
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract An examination of the literature on walking stick insects shows: sensory influences on the transition from stance to swing phase (timing influences) also influence the shape of the stance phase motor output, as far as this was tested. Therefore, the distinction between timing and shaping influences seems to be artificial in this case. The results suggest that the walking pattern generator is a relaxation oscillator.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318374
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Sensory influences on the coordination of two leg joints during searching movements of stick insects (1991)
    Springer
    Biological cybernetics 64 (1991), S. 329-335 
    Details
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract Animals (Cuniculina impigra) possessing only one foreleg with restrained coxa perform very stereotyped searching movements during which the movements of the femur-tibia and coxa-trochanter joints are well coordinated. After ablation of either hairfield BF1 (measuring the position of the coxa-trochanter joint) or the apodeme of the femoral chordotonal organ (measuring the position of the femur-tibia joint) each joint can still be moved but the coordination changes and becomes very labile. The consequences for the ideas about the construction principles of the pattern generator for searching movements are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00199597
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The network producing the “active reaction” of stick insects is a functional element of different pattern generating systems (1990)
    Springer
    Biological cybernetics 62 (1990), S. 453-462 
    Details
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract Elongation of the femoral chordotonal organ (signalling a flexion movement of the femur-tibia joint) in stick insects being active releases the active reaction (AR) in the extensor and flexor motor neurones. The AR was released in hindlegs in a situation where free animals would preferentially walk backwards. In most cases the coordination between extensor-flexor and the retractor unguis muscle was like in a stance phase of backward walking. In a situation where free animals would preferentially walk forwards, the percentage of ARs was smaller, and resistance reflexes became more frequent. When campaniform sensilla of the hind leg were destroyed coordinations like in a swing phase of forward walking became more frequent. — Additional stimuli during searching movements in an artificially closed femur-tibia feedback system (Weiland et al. 1986) showed that the AR is expressed also under these conditions and controls velocity and endpoint of a flexion movement. All results support the idea that the neural system producing the AR is a functional element of the pattern generator for forward walking, of the one for backward walking and of the one for searching movements. As far as this system is concerned the three pattern generators only differ in the kind of coordinating pathways between constant functional elements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00197651
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Interruption of searching movements of partly restrained front legs of stick insects, a model situation for the start of a stance phase? (1991)
    Springer
    Biological cybernetics 65 (1991), S. 507-514 
    Details
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract Stick insects (Cuniculina impigra) possessing only one foreleg with restrained coxa performed searching movements. A force transducer was introduced as an obstacle into the plane of movement of femur or tibia. Depending on where it was introduced and whether it was touched for the first time during an upward or a downward movement, different kinds of behaviour of the leg were released. For these different movements, the forces applied to the obstacle and the electrical activity of the depressor, levator, retractor and protractor muscles are described. In addition the alterations occurring after ablation of several sense organs including the trochanteral campaniform sensilla are mentioned. The described movements were similar to the corresponding behaviours during walking at the end of swing phase and the beginning of stance phase. Therefore there is some probability that results obtained by this experimental paradigm can also be applied to the swing-stance transition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00204664
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Der Regelkreis des Kniesehnenreflexes bei der Stabheuschrecke Carausius morosus: Reaktionen auf passive Bewegungen der Tibia (1972)
    Springer
    Biological cybernetics 12 (1972), S. 8-20 
    Details
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract 1. Passive flexion and extension of the femur-tibia-joint causes forces which are directed against the passive movements. Quantitative measurements of these forces are in accordance with the results obtained from step stimuli in open-loop-experiments (1965, 1972). Repetition of the experiments at the same joint often leads to different results: the animal is apparently able to change the amplification of the system. 2. If one brings the joint in a new position by hand, the tibia returns to its starting-point only very slowly. (Flexibilitas cerea). As a quantitative measure for Flexibilitas cerea the time interval is taken, during which a formerly fully extended joint returns to the 90°-position after a 30 sec flexion to 50° (t 90) · t 90 is not correllated with a quantitative measure of Thanatosis. Therefore it is not allowed to combine Thanatosis and Flexibilitas cerea to Katalepsis. — Legs whose receptor tendons were cut, show no Flexibilitas cerea. The behaviour of Flexibilitas cerea is explained by the attributes of the control system. 3. The reaction on very slow constant flexion and extension speeds (2,4°/sec – 0,3°/min) are described. Intact legs show a larger hysteresis at all speeds than legs with cut receptor tendons: it seems the control system reacts at those slow speeds. It responds only to the dynamic part of the movements, however not to the static one.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00289232
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Interneurones participating in the “active reaction” in stick insects (1990)
    Springer
    Biological cybernetics 62 (1990), S. 529-538 
    Details
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract The active reaction upon stimulation of the femoral chordotonal organ in stick insects is known to control velocity and endpoint of flexion movements of the femur-tibia joint (Bässler 1988). This article presents evidence that spiking interneurones in the ventral anterior median part of the adjacent ganglion participate in the generation of the active reaction as well as non-spiking interneurones in the dorsal lateral region do. Three different kinds of experiments lead to this conclusion: - Ablation of the ventral anterior median part of the metathoracic ganglion ofExtatosoma did not qualitatively alter the resistance reflex in the inactive animal but abolished the active reaction. - Recordings from spiking interneurones in the same region of the prothoracic ganglion ofCarausius show that some of these neurones responded to a chordotonal organ stimulus in a way, which depended on the behavioural state of the animal. - Some non-spiking interneurones, which mediate the resistance reflex in the inactive animal, respond differently during an active reaction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00205115
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Mass-induced oscillations in the femur-tibia control system of stick insects (1993)
    Springer
    Biological cybernetics 68 (1993), S. 259-266 
    Details
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract Attaching an inert mass to a freely moving tibia of an otherwise fixed stick insect Carausius morosus, induces undamped oscillations of the tibia. We describe the use of a rotational pendulum to observe these oscillations applying various amounts of inertia. The dependence of the frequency of these oscillations on the moment of inertia is similar to that of a purely mechanical system. The sequence of the oscillatory behavior can be separated into 3 distinct behavioural states. The transitions between some of these states could be elicited by external stimuli and partly showed characteristics of habituation and dishabituation. With a rotational pendulum on each middle leg, simultaneous oscillations of both legs were measured to investigate coupling effects between the neural control systems of the two legs. In some cases, significant coupling effects could be observed in phase and frequency. In many other cases, no coupling was found. The habituation and dishabituation effects were not transferred between the middle legs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224861
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...