Mechanisms for the Production of the Motor Output Pattern in Flying Locusts

1967 ◽  
Vol 47 (2) ◽  
pp. 201-212
Author(s):  
INGRID WALDRON
Keyword(s):  
Motor Neurons ◽  
Sensory Input ◽  
Functional Integration ◽  
Motor Units ◽  
Reciprocal Relationship ◽  
Neuron Activity ◽  
Flight Pattern ◽  
Output Pattern ◽  
Inhibitory Coupling ◽  
Relationship Of

1. The normal flight pattern consists of alternating bursts of activity in the elevator and depressor motor neurons. However, when sensory input depresses elevator activity, rhythmic bursts of activity in the depressor motor neurons may continue even after all elevator motor neuron activity has apparently ceased. Thus interactions between the antagonistic motor neurons apparently are not necessary for the production of the rhythmic bursts. The proposed mechanism for producing these rhythmic bursts depends on the excitatory interactions among the synergistic motor neurons. Alternative or supplementary explanations for the data seem to be possible only if interneurons participate in the generation of the flight pattern. 2. During flight initiation, when there is a burst of activity in several depressor motor units simultaneously there usually is a pause in the on-going elevator activity; often the normal flight pattern begins at this time. This reciprocal relationship of activity in the antagonists suggests inhibitory coupling between antagonistic motor neurons or between interneurons which may drive them. This coupling may be responsible for the alternation of the bursts of activity in the antagonists during normal flight. 3. There is no evidence for greater co-ordination within a thoracic ganglion than between ganglia. Some activity in the abdominal C.N.S. is also well co-ordinated with the flight pattern. Thus the anatomical separation into ganglia does not correspond to any interruption of the functional integration of the flight system.

Motor Patterns During Flight and Warm-up in Lepidoptera

1968 ◽  
Vol 48 (1) ◽  
pp. 89-109
Author(s):  
ANN E. KAMMER
Keyword(s):  
Motor Neurons ◽  
Muscle Activity ◽  
Motor Units ◽  
Wingbeat Frequency ◽  
Motor Patterns ◽  
Flight Pattern ◽  
Warm Up ◽  
Burst Length ◽  
Synergistic Muscles ◽  
Phase Relationships

1. The patterns of muscle activity during warm-up were compared to those of flight. In the skipper Hylephila phylaeus and in the hawk moths Celerio lineata and Mimas tiliae the intervals between bursts of muscle potentials are the same as the wingbeat periods of flight at the same thoracic temperature, and the burst length is the same as in flight. In saturniids the period and burst length are both shorter during wing-vibrating than during flight. 2. During wing-vibrating the amplitude of the wing movement is small, and some of the muscles which are antagonists in flight are active simultaneously. In Hylephila phylaeus and Celerio lineata there is a phase change between some synergistic muscles, while some antagonistic pairs retain the phase relationships of flight. During wing-vibrating in Mimas tiliae and in saturniids all the motor units sampled were active at the same time. 3. In M. tiliae a variety of phase relationships intermediate between those of wing-vibrating and flight were observed, including a case of ‘relative co-ordination’ between motor units in the mesothorax. The results exclude the possibility that a single pace-making centre drives the motor neurons in the flight pattern. 4. A model of the central nervous interactions which generate the observed motor patterns is proposed. It is postulated that a small group of positively coupled neurons produces bursts of impulses at the wingbeat frequency and that these groups interact to generate the phase relationships seen during warm-up and flight.

Multi-Joint Coordination During Walking and Foothold Searching in the Blaberus Cockroach. II. Extensor Motor Neuron Pattern

2000 ◽  
Vol 83 (6) ◽  
pp. 3337-3350 ◽  
Author(s):  
Andrew K. Tryba ◽  
Roy E. Ritzmann
Keyword(s):  
Motor Neuron ◽  
Motor Neurons ◽  
Stance Phase ◽  
Phase Relationship ◽  
Neuron Activity ◽  
Step Cycle ◽  
Joint Coordination ◽  
Stick Insects ◽  
Relationship Of ◽  
Tonic Excitation

In a previous study, we combined joint kinematics and electromyograms (EMGs) to examine the change in the phase relationship of two principal leg joints during walking and searching. In this study, we recorded intracellularly from motor neurons in semi-intact behaving animals to examine mechanisms coordinating extension at these leg joints. In particular, we examined the change in the phase of the coxa-trochanter (CTr) and femur-tibia (FT) joint extension during walking and searching. In doing so, we discovered marked similarities in the activity of CTr and FT joint extensor motor neurons at the onset of extension during searching and at the end of stance during walking. The data suggest that the same interneurons may be involved in coordinating the CTr and FT extensor motor neurons during walking and searching. Previous studies in stick insects have suggested that extensor motor neuron activity during the stance phase of walking results from an increase in tonic excitation of the neuron leading to spiking that is periodically interrupted by centrally generated inhibition. However, the CTr and FT extensor motor neuron activity during walking consists of characteristic phasic modulations in motor neuron frequency within each step cycle. The phasic increases and decreases in extensor EMG frequency during stance are associated with kinematic events (i.e., foot set-down and joint cycle transitions) during walking. Sensory feedback associated with these events might be responsible for phasic modulation of the extensor motor neuron frequency. However, our data rule out the possibility that sensory cues resulting from foot set-down are responsible for a decline in CTr extensor activity that is characteristic of the Blaberusstep cycle. Our data also suggest that both phasic excitation and inhibition contribute to extensor motor neuron activity during the stance phase of walking.

Bifunctional Muscles in the Thorax of Grasshoppers

1962 ◽  
Vol 39 (4) ◽  
pp. 669-677
Author(s):  
DONALD M. WILSON
Keyword(s):  
Electrical Activity ◽  
Motor Neurons ◽  
Motor Units ◽  
Flight Pattern ◽  
Fixed Set ◽  
Complete Independence

1. Recording electrical activity of certain dorso-ventral muscles in the thorax of grasshoppers has shown that the same muscles and (in at least one muscle) the same motor units may be used to move either the wings or the legs. 2. The anatomical connexions are such that muscles which are antagonists with respect to the wings are synergists with respect to the legs, and vice versa. 3. These muscles, which operate in a nearly perfectly repeating, fixed pattern during flight, show complete independence during manœuvres involving the legs and it is concluded that the flight pattern is not due to a fixed set of connexions between the motor neurons.

scholarly journals Reduction Mechanism of Fine Hematite Ore Particles in Suspension

2021 ◽  
Author(s):  
Zhiyuan Chen ◽  
Christiaan Zeilstra ◽  
Jan van der Stel ◽  
Jilt Sietsma ◽  
Yongxiang Yang
Keyword(s):  
Particle Size ◽  
Temperature Drop ◽  
Reduction Rate ◽  
Reduction Process ◽  
Reciprocal Relationship ◽  
Drop Tube ◽  
Surface Nucleation ◽  
Order Of Magnitude ◽  
Relationship Of ◽  
Kinetics Of

AbstractIn order to understand the pre-reduction behaviour of fine hematite particles in the HIsarna process, change of morphology, phase and crystallography during the reduction were investigated in the high temperature drop tube furnace. Polycrystalline magnetite shell formed within 200 ms during the reduction. The grain size of the magnetite is in the order of magnitude of 10 µm. Lath magnetite was observed in the partly reduced samples. The grain boundary of magnetite was reduced to molten FeO firstly, and then the particle turned to be a droplet. The Johnson-Mehl-Avrami-Kolmogorov model is proposed to describe the kinetics of the reduction process. Both bulk and surface nucleation occurred during the reduction, which leads to the effect of size on the reduction rate in the nucleation and growth process. As a result, the reduction rate constant of hematite particles increases with the increasing particle size until 85 µm. It then decreases with a reciprocal relationship of the particle size above 85 µm.

Substrate Stabilization: Genetically Controlled Reciprocal Relationship of Two Human Enzymes

Science ◽  
1970 ◽  
Vol 167 (3919) ◽  
pp. 887-889 ◽  
Author(s):  
M. L. Greene ◽  
J. A. Boyle ◽  
J. E. Seegmiller
Keyword(s):  
Reciprocal Relationship ◽  
Substrate Stabilization ◽  
Relationship Of

scholarly journals Grid Governance in China under the COVID-19 Outbreak: Changing Neighborhood Governance

2021 ◽  
Vol 13 (13) ◽  
pp. 7089
Author(s):  
Tianke Zhu ◽  
Xigang Zhu ◽  
Jian Jin
Keyword(s):  
State Government ◽  
Local Governance ◽  
The State ◽  
Reciprocal Relationship ◽  
Private Governance ◽  
Neighborhood Organizations ◽  
Housing Privatization ◽  
Epidemic Period ◽  
Neighborhood Governance ◽  
Relationship Of

Housing commodification seems to suggest that a process of a state is embracing private governance. However, private governance in Chinese neighborhoods is a two-way trajectory. This paper examined two types of housing neighborhoods, namely, a work-unit housing neighborhood and gated commodity housing to understand the changes in neighborhood governance. It is interesting to observe that during the Covid-19 epidemic period, the state government enhanced its presence and public trust in neighborhood governance by changing the former ways of self-governance. As a strategy for the state to return to local governance, the grid governance is the reconfiguration of administrative resources at a neighborhood level and professionalizes neighborhood organizations to ensure the capacities of the state to solve social crises and neighborhood governance. The potential side effects of changing neighborhood governance are that while the implementation of grid governance has improved internal connections among residents, the empowered neighborhood governments acting as the “state agent on the ground” leads to an estrangement between residents and private governance. The underdevelopment of neighborhood autonomy is not only due to the restriction of state government, but more importantly, the reciprocal relationship of state-led neighborhood governance in the context of housing privatization development in China.

TV or Not TV: Fat Is the Question

PEDIATRICS ◽  
1993 ◽  
Vol 91 (2) ◽  
pp. 499-501
Author(s):  
WILLIAM H. DIETZ ◽  
STEVEN L. GORTMAKER
Keyword(s):  
Physical Activity ◽  
Body Mass Index ◽  
Body Mass ◽  
Adolescent Girls ◽  
Television Viewing ◽  
Physical Activities ◽  
Reciprocal Relationship ◽  
Seventh Grade ◽  
Relationship Of

The manuscript entitled "Does television viewing increase obesity and reduce physical activity?" published by Robinson and coauthors in this issue of Pediatrics1 is a careful and well-written study of the effect of television viewing on adiposity and physical activity among sixth- and seventh-grade adolescent girls. In contrast to two other large studies of children,2,3 the authors failed to find a significant association between hours of television viewed and adiposity, measured by body mass index. Physical activity was weakly and inversely correlated to time spent viewing television. The latter observation is consistent with prior data which demonstrate a reciprocal relationship of fitness and television viewing,4 perhaps because television viewing displaces more vigorous physical activities.5

scholarly journals Reciprocal relationship of synovial fluid volume and Oxygen tension

1981 ◽  
Vol 24 (5) ◽  
pp. 701-705 ◽  
Author(s):  
Alan I. Richman ◽  
Eugene Y. Su ◽  
George Ho
Keyword(s):  
Synovial Fluid ◽  
Oxygen Tension ◽  
Fluid Volume ◽  
Reciprocal Relationship ◽  
Relationship Of

Aplysia ink release: central locus for selective sensitivity to long-duration stimuli

1979 ◽  
Vol 42 (5) ◽  
pp. 1223-1232 ◽  
Author(s):  
E. Shapiro ◽  
J. Koester ◽  
J. H. Byrne
Keyword(s):  
Motor Neuron ◽  
Spike Train ◽  
Motor Neurons ◽  
Neural Circuit ◽  
Reversal Potential ◽  
Secretory Process ◽  
Neuron Activity ◽  
Long Duration ◽  
Noxious Stimuli ◽  
Selective Sensitivity

1. A behavioral and electrophysiological analysis of defensive ink release in Aplysia californica was performed to examine the response of this behavior and its underlying neural circuit to various-duration noxious stimuli. 2. Three separate behavioral protocols were employed using electrical shocks to the head as noxious stimuli to elicit ink release. Ink release was found to be selectively responsive to longer duration stimuli, and to increase in a steeply graded fashion as duration is increased. 3. Intracellular stimulation of ink motor neurons revealed that ink release is a linear function of motor neuron spike train duration, indicating that the selective sensitivity of the behavior to long-duration stimuli is not due to a nonlinearity in the glandular secretory process. 4. In contrast, electrophysiological examination of ink motor neuron activity in response to sustained head shock revealed an accelerating spike train. During the later part of the spike train, compound excitatory synaptic potentials show a positive shift in reversal potential. 5. Our results suggest a central locus for the mechanisms that determine sensitivity of inking behavior to stimulus duration. 6. In contrast to ink release, defensive gill withdrawal was found to be extremely sensitive to short-duration stimuli.

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