Common motor mechanisms support body load in serially homologous legs of cockroaches in posture and walking

Quimby, Laura; Amer, Ayman; Zill, Sasha N.

doi:10.1007/s00359-005-0062-9

Cited by 20 publications

(13 citation statements)

References 73 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…CTr-joint induced by middle leg CS stimulation Load signals such as those signaled by the CS have been known for some time now to play an important role in the coordination of the activities of the CPGs associated with the different joints of a single insect leg (e.g., Akay et al 2004;Daun-Gruhn 2011;Noah et al 2004;Quimby et al 2006;Ridgel et al 1999;Schmitz 1993;Zill et al 2011; for review see: Büschges and Gruhn 2008;Zill et al 2004) as well as in generating a coordinated walking pattern between all six legs of an intact walking animal (e.g., Zill et al 2009). For the stick insect leg, so far three locations with several fields and subgroups of CS have been described: trochanteral CS (trCS) (Hofmann and Bässler 1982), femoral CS (feCS) on the proximal femur (Schmitz et al 1991), and tibial CS (tiCS) (Zill et al 2011).…”

Section: Rhythmic Activity In the Cpg Of The Middle Legmentioning

confidence: 99%

Dominance of local sensory signals over inter-segmental effects in a motor system: experiments

et al. 2011

View full text Add to dashboard Cite

Legged locomotion requires that information local to one leg, and inter-segmental signals coming from the other legs are processed appropriately to establish a coordinated walking pattern.However, very little is known about the relative importance of local and inter-segmental signals when they converge upon the central pattern generators (CPGs) of different leg joints.We investigated this question on the CPG of the middle leg coxa–trochanter (CTr)-joint of the stick insect which is responsible for lifting and lowering the leg.We used a semi-intact preparation with an intact front leg stepping on a treadmill, and simultaneously stimulated load sensors of the middle leg.We found that middle leg load signals induce bursts in the middle leg depressor motoneurons(MNs). The same local load signals could also elicit rhythmic activity in the CPG of the middle leg CTr-joint when the stimulation of middle leg load sensors coincided with front leg stepping. However, the influence of front leg stepping was generally weak such that front leg stepping alone was only rarely accompanied by switching between middle leg levator and depressor MN activity. We therefore conclude that the impact of the local sensory signals on the levator–depressor motor system is stronger than the inter-segmental influence through front leg stepping.

show abstract

Section: Rhythmic Activity In the Cpg Of The Middle Legmentioning

confidence: 99%

Dominance of local sensory signals over inter-segmental effects in a motor system: experiments

et al. 2011

View full text Add to dashboard Cite

show abstract

“…In insects, the smaller front legs are used under direct visual control to guide behaviours such as grasping of food and exploration of surfaces during walking, whereas the more massive hind legs allow generation of large forces and movements in the horizontal plane for escape running (Quimby et al, 2006). Despite these differences, studies of sensory encoding of load in cockroaches indicate that motor responses to different load signals are similar in each of the serially homologous legs (Quimby et al, 2006). (Hughes, 1952;Spirito and Mushrush, 1979).…”

Section: Leg-specific Contributions Of Proprioceptive Inputsmentioning

confidence: 99%

Proprioceptive feedback reinforces centrally generated stepping patterns in the cockroach

Fuchs

Holmes

David

et al. 2012

Journal of Experimental Biology

View full text Add to dashboard Cite

SUMMARYThe relative importance of sensory input for the production of centrally generated motor patterns is crucial to our understanding of how animals coordinate their body segments to locomote. In legged locomotion, where terrain heterogeneity may require stride-by-stride changes in leg placement, evidence suggests that sensory information is essential for the timing of leg movement. In a previous study we showed that in cockroaches, renowned for rapid and stable running, a coordinated pattern can be elicited from the motor centres driving the different legs in the absence of sensory feedback. In the present paper, we assess the role of movement-related sensory inputs in modifying this central pattern. We studied the effect of spontaneous steps as well as imposed transient and periodic movements of a single intact leg, and demonstrate that, depending on the movement properties, the resulting proprioceptive feedback can significantly modify phase relationships among segmental oscillators of other legs. Our analysis suggests that feedback from front legs is weaker but more phasically precise than from hind legs, selectively transferring movement-related information in a manner that strengthens the inherent rhythmic pattern and modulates local perturbations.

show abstract

“…In cockroach different subgroups of tibial campaniform sensilla react to increases or decreases in body load (Noah et al 2004;Zill et al 2009) and fire prolonged spike trains when legs actively support the body. Increased load also increases cockroach trochanteral extensor motoneuron firing, the functional analog of stick insect depressor motoneurons (Quimby et al 2006). These and our data suggest that local mechanisms controlling depressor activity are a major component of the support of body load and maintenance of body height.…”

Section: Local Influence On Depressor Muscle Activitymentioning

confidence: 99%

Activity Patterns and Timing of Muscle Activity in the Forward Walking and Backward Walking Stick InsectCarausius morosus

Rosenbaum

Wosnitza

Büschges

et al. 2010

Journal of Neurophysiology

View full text Add to dashboard Cite

Rosenbaum P, Wosnitza A, Büschges A, Gruhn M. Activity patterns and timing of muscle activity in the forward walking and backward walking stick insect Carausius morosus. J Neurophysiol 104: 1681-1695, 2010. First published July 28, 2010 doi:10.1152/jn.00362.2010. Understanding how animals control locomotion in different behaviors requires understanding both the kinematics of leg movements and the neural activity underlying these movements. Stick insect leg kinematics differ in forward and backward walking. Describing leg muscle activity in these behaviors is a first step toward understanding the neuronal basis for these differences. We report here the phasing of EMG activities and latencies of first spikes relative to precise electrical measurements of middle leg tarsus touchdown and liftoff of three pairs (protractor/ retractor coxae, levator/depressor trochanteris, extensor/flexor tibiae) of stick insect middle leg antagonistic muscles that play central roles in generating leg movements during forward and backward straight walking. Forward walking stance phase muscle (depressor, flexor, and retractor) activities were tightly coupled to touchdown, beginning on average 93 ms prior to and 9 and 35 ms after touchdown, respectively. Forward walking swing phase muscle (levator, extensor, and protractor) activities were less tightly coupled to liftoff, beginning on average 100, 67, and 37 ms before liftoff, respectively. In backward walking the protractor/retractor muscles reversed their phasing compared with forward walking, with the retractor being active during swing and the protractor during stance. Comparison of intact animal and reduced two-and one-middle-leg preparations during forward straight walking showed only small alterations in overall EMG activity but changes in first spike latencies in most muscles. Changing body height, most likely due to changes in leg joint loading, altered the intensity, but not the timing, of depressor muscle activity.

show abstract

Common motor mechanisms support body load in serially homologous legs of cockroaches in posture and walking

Cited by 20 publications

References 73 publications

Dominance of local sensory signals over inter-segmental effects in a motor system: experiments

Dominance of local sensory signals over inter-segmental effects in a motor system: experiments

Proprioceptive feedback reinforces centrally generated stepping patterns in the cockroach

Activity Patterns and Timing of Muscle Activity in the Forward Walking and Backward Walking Stick InsectCarausius morosus

Contact Info

Product

Resources

About