Muscle Activity During Flight in Some large Lepidoptera

1967 ◽  
Vol 47 (2) ◽  
pp. 277-295
Author(s):  
ANN E. KAMMER
Keyword(s):  
Motor Unit ◽  
Muscle Activity ◽  
Sensory Nerves ◽  
Single Model ◽  
Motor Patterns ◽  
Wing Movement ◽  
Burst Length ◽  
Partial Amputation ◽  
Flight Muscles ◽  
Stroke Amplitude

1. The names and functions of the main mesothoracic flight muscles in Lepidoptera are reviewed. 2. The wingbeat period in saturniid moths and monarch butterflies is long and variable. The three parameters, wingbeat period, burst length (number of times a motor unit is activated per wingstroke) and stroke amplitude are interdependent and positively correlated. 3. Partial amputation of the wings in saturniids decreases wingbeat period. Cutting the sensory nerves from the wings increases the period. These results indicate that the influence of wing movement on wingbeat period is mediated by receptors near the base of the wing. 4. The central nervous mechanisms which generate motor patterns during flight in Lepidoptera are discussed and compared with those in locusts. It is proposed that both mechanisms can be described by a single model, with minor differences in the mechanism of burst production.

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.

Timing of elevator muscle activity during climbing in free locust flight

1999 ◽  
Vol 202 (24) ◽  
pp. 3575-3586 ◽  
Author(s):  
H. Fischer ◽  
W. Kutsch
Keyword(s):  
Muscle Activity ◽  
Closed Loop ◽  
Schistocerca Gregaria ◽  
Motor Pattern ◽  
Detailed Knowledge ◽  
Free Flight ◽  
Flight Muscles ◽  
Flight Motor ◽  
Stroke Amplitude ◽  
Aerodynamic Lift

Despite detailed knowledge of the sensory-motor interactions during elevator muscle timing for the generation of a ‘functional’ flight motor pattern in flying locusts, there is little information about how a possible shift in the onset of elevator activity is correlated with changes in flight variables under closed-loop conditions (i.e. during free flight). Free-flight variables were investigated with respect to ascent angle during climbing flight in locusts Schistocerca gregaria. The motor pattern during free flight was examined by telemetric electromyography of particular antagonistic flight muscles in both ipsilateral hemisegments of the pterothorax while flight variables were recorded simultaneously on video. In the majority of the animals tested, the onset of elevator muscle activity within the wingbeat cycle is delayed when animals increase their ascent angle during climbing flight. In accordance with the motor pattern, the downstroke phase and the stroke amplitude of the wings increased with increasing the ascent angle. This suggests that the relative elevator timing during the wingbeat cycle may be related to the generation of the additional aerodynamic lift required for ascending flight and may, therefore, play a role in the regulation of ascent angle during free flight in the locust.

Brain stem integration of vocalization: role of the midbrain periaqueductal gray

1994 ◽  
Vol 72 (3) ◽  
pp. 1337-1356 ◽  
Author(s):  
S. P. Zhang ◽  
P. J. Davis ◽  
R. Bandler ◽  
P. Carrive
Keyword(s):  
Muscle Activity ◽  
Sound Production ◽  
Type A ◽  
Periaqueductal Gray ◽  
Emg Activity ◽  
Digastric Muscle ◽  
Type B ◽  
Motor Patterns ◽  
Homocysteic Acid ◽  
Lower Amplitude

1. The contribution of the midbrain periaqueductal gray (PAG) to the central regulation of vocalization was investigated by analyzing the electromyographic (EMG) changes in respiratory, laryngeal, and oral muscles evoked by microinjection of D,L-homocysteic acid (DLH) in the PAG of unanesthetized, precollicular decerebrate cats. Moderate to large (6-40 nmol) doses of DLH evoked natural-sounding vocalization as well as increases in inspiratory depth and respiratory rate. 2. Two basic types of vocalization were evoked, each associated with a distinct and characteristic pattern of respiratory, laryngeal and oral EMG changes. Type A vocalization (voiced sounds such as howl/mew/growl) was characterized by excitation of the cricothyroid (CT) and thyro-arytenoid (TA) muscles, and inhibition of the posterior crico-arytenoid (PCA) muscle, whereas type B vocalization (unvoiced hiss sounds) was characterized by excitation of the PCA and TA muscles and no significant activation of the CT muscle. In addition, stronger expiratory (external oblique, internal oblique, internal intercostal) EMG increases were associated with type A responses, and larger increases in genioglossus and digastric muscle activity were associated with type B responses. 3. Microinjections of small doses of DLH (300 pmol-3 nmol), also evoked patterned changes in muscle activity (usually without audible vocalization) that, although of lower amplitude, were identical to those evoked by injections of moderate to large DLH doses. In no such experiments (175 sites) were individual muscles activated by small dose injections of DLH into the PAG. Further, type A vocalization/muscle patterns were evoked from PAG sites caudal to those at which type B vocalization/muscle patterns were evoked. 4. Considered together these results indicate: that the PAG contains topographically separable groups of neurons that coordinate laryngeal, respiratory, and oral muscle patterns characteristic of two fundamental types of vocalization and that the underlying PAG organization takes the form of a representation of muscle patterns, rather than individual muscles. 5. The patterns of EMG activity evoked by excitation of PAG neurons were strikingly similar to previously reported patterns of EMG activity characteristic of major phonatory categories in higher species, including humans (e.g., vowel phonation, voiceless consonant phonation). These findings raise the possibility that the sound production circuitry of the PAG could well be utilized by cortical and subcortical "language structures" to coordinate basic respiratory and laryngeal motor patterns that are necessary for speech.

The effects of temperature on the burial performance and axial motor pattern of the sand-swimming of the Mojave fringe-toed lizard Uma scoparia

2000 ◽  
Vol 203 (7) ◽  
pp. 1241-1252 ◽  
Author(s):  
B.C. Jayne ◽  
M.W. Daggy
Keyword(s):  
Muscle Activity ◽  
Motor Pattern ◽  
Wave Pattern ◽  
Motor Patterns ◽  
Axial Muscle ◽  
Hind Limbs ◽  
Anterior Trunk ◽  
Cycling Frequency ◽  
The Mean ◽  
Similar Motor

Although lateral axial bending is widespread for the locomotion of ectothermic vertebrates, the axial motor patterns of terrestrial taxa are known only for a limited number of species and behaviors. Furthermore, the extent to which the trunk and tail of ectothermic tetrapods have similar motor patterns is poorly documented. We therefore recorded the activity of the epaxial muscles in the trunk and tail of sand-swimming Mojave fringe-toed lizards (Uma scoparia) to determine whether this specialized behavior has features of the motor pattern that differ from those of diverse ectothermic vertebrates. Muscle activity during initial sand-swimming was a standing-wave pattern in the trunk and tail. Next, the hind limbs moved alternately and the caudofemoralis muscles and nearby axial muscle in the trunk and tail had similar long-duration electromyographic bursts, whereas the anterior trunk had shorter, more frequent electromyographic bursts. The final tail burial involved a traveling wave of posteriorly propagated axial muscle activity within localized regions of the tail. With increased temperature (from 22 to 40 degrees C), the mean frequencies of axial oscillations increased from approximately 7 to 21 Hz, and the greatest value (33 Hz) was nearly twice the maximal limb cycling frequency during running. The mean burial time at the lowest temperature (3.8 s) was nearly twice that for a 10 degrees C higher temperature. For the axial electromyograms, a decrease in temperature of 18 degrees C more than doubled the electromyographic and cycle durations, whereas the duty factors and intersegmental phase lags changed only slightly with temperature.

Motor patterns of labriform locomotion: kinematic and electromyographic analysis of pectoral fin swimming in the labrid fish Gomphosus varius

1997 ◽  
Vol 200 (13) ◽  
pp. 1881-1893 ◽  
Author(s):  
M Westneat ◽  
J Walker
Keyword(s):  
Muscle Activity ◽  
Motor Pattern ◽  
Onset Time ◽  
Total Body Length ◽  
Adductor Muscle ◽  
Pectoral Fin ◽  
Motor Patterns ◽  
Emg Patterns ◽  
Muscle Groups ◽  
Electromyographic Analysis

Labriform locomotion is a widespread swimming mechanism in fishes during which propulsive forces are generated by oscillating the pectoral fins. We examined the activity of the six major muscles that power the pectoral fin of the bird wrasse Gomphosus varius (Labridae: Perciformes). The muscles studied included the fin abductors (arrector ventralis, abductor superficialis and abductor profundus) and the fin adductors (arrector dorsalis, adductor superficialis and adductor profundus). Our goals were to determine the pattern of muscle activity that drives the fins in abduction and adduction cycles during pectoral fin locomotion, to examine changes in the timing and amplitude of electromyographic (EMG) patterns with increases in swimming speed and to correlate EMG patterns with the kinematics of pectoral fin propulsion. EMG data were recorded from three individuals over a range of swimming speeds from 15 to 70 cm s-1 (1­4.8 TL s-1, where TL is total body length). The basic motor pattern of pectoral propulsion is alternating activity of the antagonist abductor and adductor groups. The downstroke is characterized by activity of the arrector ventralis muscle before the other abductors, whereas the upstroke involves nearly synchronous activity of the three adductors. Most EMG variables (duration, onset time, amplitude and integrated area) showed significant correlations with swimming speeds. However, the timing and duration of muscle activity are relatively constant across speeds when expressed as a fraction of the stride period, which decreases with increased velocity. Synchronous recordings of kinematic data (maximal abduction and adduction) with EMG data revealed that activity in the abductors began after maximal adduction and that activity in the adductors began nearly synchronously with maximal abduction. Thus, the pectoral fin mechanism of G. varius is activated by positive work from both abductor and adductor muscle groups over most of the range of swimming speeds. The adductors produce some negative work only at the highest swimming velocities. We combine information from pectoral fin morphology, swimming kinematics and motor patterns to interpret the musculoskeletal mechanism of pectoral propulsion in labrid fishes.

scholarly journals Muscle fibre recruitment can respond to the mechanics of the muscle contraction

2006 ◽  
Vol 3 (9) ◽  
pp. 533-544 ◽  
Author(s):  
James M Wakeling ◽  
Katrin Uehli ◽  
Antra I Rozitis
Keyword(s):  
Motor Unit ◽  
Muscle Activity ◽  
The Body ◽  
Motor Unit Recruitment ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Muscle Fibres ◽  
Strain Rates ◽  
Lower Velocity ◽  
Muscle Fascicle

This study investigates the motor unit recruitment patterns between and within muscles of the triceps surae during cycling on a stationary ergometer at a range of pedal speeds and resistances. Muscle activity was measured from the soleus (SOL), medial gastrocnemius (MG) and lateral gastrocnemius (LG) using surface electromyography (EMG) and quantified using wavelet and principal component analysis. Muscle fascicle strain rates were quantified using ultrasonography, and the muscle–tendon unit lengths were calculated from the segmental kinematics. The EMG intensities showed that the body uses the SOL relatively more for the higher-force, lower-velocity contractions than the MG and LG. The EMG spectra showed a shift to higher frequencies at faster muscle fascicle strain rates for MG: these shifts were independent of the level of muscle activity, the locomotor load and the muscle fascicle strain. These results indicated that a selective recruitment of the faster motor units occurred within the MG muscle in response to the increasing muscle fascicle strain rates. This preferential recruitment of the faster fibres for the faster tasks indicates that in some circumstances motor unit recruitment during locomotion can match the contractile properties of the muscle fibres to the mechanical demands of the contraction.

Torso and Hip Muscle Activity and Resulting Spine Load and Stability while Using the ProFitter 3-D Cross Trainer

2009 ◽  
Vol 25 (1) ◽  
pp. 73-84 ◽  
Author(s):  
Priyanka Banerjee ◽  
Stephen H.M Brown ◽  
Samuel J. Howarth ◽  
Stuart M. McGill
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Clinical Decision Making ◽  
Dynamic Balance ◽  
Gluteus Medius ◽  
Clinical Decision ◽  
Whole Body ◽  
Motor Patterns ◽  
Hip Muscle ◽  
Spine Mechanics

The ProFitter 3-D Cross Trainer is a labile surface device used in the clinic and claimed to train spine stability. The purpose of this study was to quantify the spine mechanics (compression and shear forces and stability), together with muscle activation mechanics (surface electromyography) of the torso and hip, during three ProFitter exercises. Trunk muscle activity was relatively low while exercising on the device (<25%MVC). Gluteus medius activity was phasic with the horizontal sliding position, especially for an experienced participant. Sufficient spinal stability was achieved in all three exercise conditions. Peak spinal compression values were below 3400 N (maximum 3188 N) and peak shear values were correspondingly low (under 500 N). The exercises challenge whole-body dynamic balance while producing very conservative spine loads. The motion simultaneously integrates hip and torso muscles in a way that appears to ensure stabilizing motor patterns in the spine. This information will assist with clinical decision making about the utility of the device and exercise technique in rehabilitation and training programs.

Neural Mechanism by Which Controlling Inputs Influence Motor Output in the Flying Locust

1967 ◽  
Vol 47 (2) ◽  
pp. 213-228
Author(s):  
INGRID WALDRON
Keyword(s):  
Motor Neuron ◽  
Motor Neurons ◽  
Neural Mechanism ◽  
Sensory Nerves ◽  
Rapid Variation ◽  
Flight Pattern ◽  
Burst Length ◽  
Rapid Changes ◽  
Length Changes ◽  
Individual Motor

1. The central nervous system of the flying locust generates a pattern of alternating bursts of impulses in the elevator and depressor motor neurons (Wilson, 1961). The mechanism by which controlling inputs modify this output pattern is analysed in this paper. 2. During roll turns and other flight manoeuvres the average number of impulses per burst (average burst length) changes in certain motor neurons. Changes in average burst length develop slowly, over tens of wingbeat cycles, even in response to the abrupt changes in input which result from electrical stimulation of sensory nerves. 3. In addition to the slow changes in average burst length which are elicited by controlling inputs, more rapid changes in burst length sometimes occur. During this rapid variation a longer burst is usually followed by a shorter burst, probably because the motor neuron is less excitable after a longer burst of activity. Burst length varies independently in different motor neurons. Both findings suggest that much of the rapid variation in burst length is due to changes occurring within the individual motor neurons, and is not a response to rapid changes in controlling inputs. 4. Under all conditions, changes in the number of impulses per burst are correlated with small changes in the relative timing of the burst; the longer bursts produced by a motor neuron begin slightly earlier in the wingbeat cycle. This implies that the factors which cause variation in the length of the bursts are also responsible for producing the variation in the timing of the bursts. 5. All of the observations can be explained on one assumption: that the only effect of controlling inputs is to cause slow changes in the ‘average excitation’ of individual motor neurons. Thus sensory and central control of the flight pattern generating system appears to be slow control over the average performance, rather than fast control over performance in a particular cycle.

Prey Processing in Haemulid Fishes: Patterns of Variation in Pharyngeal Jaw Muscle Activity

1989 ◽  
Vol 141 (1) ◽  
pp. 359-375 ◽  
Author(s):  
PETER C. WAINWRIGHT
Keyword(s):  
Muscle Activity ◽  
Activity Patterns ◽  
Motor Pattern ◽  
Prey Type ◽  
Motor Patterns ◽  
Fish Family ◽  
Treatment Groups ◽  
Jaw Muscle ◽  
Species Effect ◽  
Pharyngeal Jaw

This study examines patterns of variation in 15 electromyographic (EMG) variables measured from recordings of pharyngeal jaw muscle activity during prey processing in four species of the perciform fish family Haemulidae. Two questions were of primary interest. (1) Are motor patterns conserved across the four species? (2) Do the fishes alter (modulate) muscle activity patterns when feeding on different prey types? The experimental design used allowed the partitioning of variance in EMG variables among species, among individuals within species, among days within individuals, among feedings within days, and among prey types. Only one variable exhibited a significant species effect, indicating that the four species used virtually the same motor pattern during prey processing. In response to three prey types differing in hardness, all four species demonstrated an ability to modulate several EMG variables that characterized the intensity of electrical activity. However, variables characterizing the relative timing of muscle activities were not influenced by prey type. A significant variance component was found among recording days and, together with the possibility of variation among experimental preparations, this raises questions about the extent of previously reported inter-individual variation in EMGs. These results support a growing data base on aquatic feeding in lower vertebrates which finds that: (1) motor patterns tend to be highly conserved among closely related taxa; (2) the ability to modulate motor patterns in response to different prey types appears to be a general property of teleost fish feeding mechanisms; and (3) variation in experimental EMG data is ubiquitous and, when unaccounted for, confounds comparisons among treatment groups.

Neural Control of Fibrillar Muscles in Bees During Shivering and Flight

1991 ◽  
Vol 159 (1) ◽  
pp. 419-431 ◽  
Author(s):  
HARALD ESCH ◽  
FRANZ GOLLER
Keyword(s):  
Muscle Activity ◽  
Neural Control ◽  
Stretch Activation ◽  
Warm Up ◽  
Modes Of Action ◽  
Flight Muscles ◽  
First Time ◽  
Longitudinal Muscles ◽  
Shivering Thermogenesis ◽  
Muscle Potential

The big indirect flight muscles in the thorax of honeybees and bumblebees show two modes of action: they contract with ‘conventional’ twitches in response to slowly repeated muscle potentials and go into tetanus at higher muscle potential frequencies. They can also contract much faster when quickly stretched (stretch activation). We observed contractions of DV (dorsoventral) and DL (dorsal longitudinal) muscles optically with the help of a tiny mirror glued to the scutellum. We noticed that DL muscles contracted much more than DV muscles during pre-flight warmup. During warm-up, muscle potential frequencies in DL muscles were higher than in DV muscles (DL frequency/DV frequency =1.3), whereas during flight the ratio reversed (DL/DV=0.8). The scutal fissure was completely closed during shivering warm-up, apparently because the DL muscles shortened as much as they could. As a consequence, fast antagonistic stretching was not possible. However, the scutal fissure oscillated between wide open and closed during flight, and antagonists could stretch each other quickly. Flight was started by highly synchronized ‘conventional’ contractions of many muscle elements in DV muscles. Antagonistic stretch-activation during flight led to faster shortening than during shivering warm-up and synchronized all activated muscle elements to produce maximal contractions. The indirect flight muscles of bumblebees were in tetanic contractions during shivering warm-up over the whole range of temperatures between 8 and 36°C. These tetanic contractions probably prevented other researchers from observing mechanical muscle activity. Our results, which for the first time allow us to detect tetanic contractions directly, make it very improbable that non-shivering thermogenesis occurs in bumblebees, as has been proposed previously.

Sign in / Sign up

Export Citation Format

Share Document