The behavior of the proprioceptors of the muscle and the innervation of the fusimotor system during cold shivering

1973 ◽  
Vol 17 (4) ◽  
Author(s):  
SonjaS. Sch�fer ◽  
S. Sch�fer
Author(s):  
K-E. Hagbarth ◽  
V. G. Macefield
Keyword(s):  

1981 ◽  
Vol 13 (2) ◽  
pp. 78
Author(s):  
H. A. deVries ◽  
C. P. Simard ◽  
R. A. Wiswell ◽  
E. Heckathorae ◽  
V. Carabetta

Author(s):  
Peter Ellaway ◽  
Anthony Taylor ◽  
Rade Durbaba ◽  
Stephen Rawlinson
Keyword(s):  

1985 ◽  
Vol 54 (3) ◽  
pp. 578-591 ◽  
Author(s):  
G. E. Loeb ◽  
J. A. Hoffer ◽  
W. B. Marks

Chronically implanted electrodes were used to record the activity of identified single muscle spindle afferents in awake cats during responses to various types of manual and electrical stimulation. During vigorous cyclical responses such as shaking and scratching, spindle afferents generally maintained at least some activity during both lengthening and shortening of the parent muscle, indicating that the programs for these movements include both extra- and intrafusal recruitment. During noncyclical responses such as ipsilateral limb withdrawal and crossed-extension, spindle activity was modest and poorly correlated with extrafusal activity. Weak cutaneous nerve shocks during walking elicited complex excitatory and inhibitory phase-dependent reflexes in the various muscles studied but caused relatively little change in spindle afferent activity, indicating a lack of correlation between alpha and gamma motoneuron activity. A primary and a secondary afferent from sartorius muscle were recorded simultaneously during walking cycles that were perturbed by electrically induced twitches of the antagonist hamstring muscles; both demonstrated highly sensitive, short latency responses to the resulting skeletal motion, consistent with their previously suggested roles in detecting small brief mechanical perturbations. The degree to which fusimotor responses were correlated with extrafusal responses to somatosensory perturbations was highly dependent on the specific nature of the stimulus and the response. Fusimotor reprogramming of the spindle sensitivity appears to be a feature of cyclical movements that are presumably under proprioceptive control, whereas brief perturbations within the context of a particular motor program may be ignored by the fusimotor system.


1985 ◽  
Vol 249 (5) ◽  
pp. R533-R538 ◽  
Author(s):  
H. Barre ◽  
A. Geloen ◽  
J. Chatonnet ◽  
A. Dittmar ◽  
J. L. Rouanet

The capacity for nonshivering thermogenesis (NST) was examined in 26- to 27-day cold-acclimated (CA) muscovy ducklings reared for 21 days at 4 degrees C. Metabolic rate and integrated electromyographic (EMG) muscle activity were measured at ambient temperature ranging from -10 to 28 degrees C. Compared with controls reared at 30 degrees C, CA ducklings were more resistant to cold and had higher peak metabolic rate in extreme cold. Shivering threshold temperature of CA ducklings was 14.2 degrees C lower than lower critical temperature, whereas for controls the two temperatures were similar. Thus CA ducklings exhibited an NST in moderate cold. In addition, at temperatures that produced shivering, EMG activity in CA duckling muscle was lesser than that of controls, even at a higher metabolic rate. Because these ducklings are devoid of brown adipose tissue, these results indicated an increased thermogenic efficiency of muscular activity in CA ducklings.


2021 ◽  
Author(s):  
Sinan Kaya-Zeeb ◽  
Lorenz Engelmayer ◽  
Jasmin Bayer ◽  
Heike Bähre ◽  
Roland Seifert ◽  
...  

In times of environmental change species have two options to survive: they either relocate to a new habitat or they adapt to the altered environment. Adaptation requires physiological plasticity and provides a selection benefit. In this regard, the Western honeybee (Apis mellifera) protrudes with its thermoregulatory capabilities, which enables a nearly worldwide distribution. Especially in the cold, shivering thermogenesis enables foraging as well as proper brood development and thus survival. In this study, we present octopamine signaling as a neurochemical prerequisite for honeybee thermogenesis: we were able to induce hypothermia by depleting octopamine in the flight muscles. Additionally, we could restore the ability to increase body temperature by administering octopamine. Thus we conclude, that octopamine is necessary and sufficient for thermogenesis. Moreover, we show that these effects are mediated by β octopamine receptors. The significance of our results is highlighted by the fact the respective receptor genes underlie enormous selective pressure due to adaptation to cold climates. Finally, octopamine signaling in the service of thermogenesis might be a key strategy to survive in a changing environment.


1986 ◽  
Vol 64 (4) ◽  
pp. 499-504 ◽  
Author(s):  
Arthur Prochazka

In the last decade, a number of laboratories have accumulated data on the firing of single afferent fibres from muscle and skin during movement in awake cats, monkeys and human subjects. While there is general agreement on the firing behaviour of skin afferents and tendon organ (Ib) afferents during movement, there remains a significant divergence of opinion regarding the way in which the response of muscle spindle afferents (Ia and II) to length changes is modified by fusimotor action (e.g., alpha–gamma linkage versus "fusimotor set"). The controversies surrounding the fusimotor system have tended to overshadow the emergence of several important characteristics of propioceptive behaviour, corroborated in separate laboratories, (i) Mean la firing rates during active movements are nearly always higher than at rest. Thus, activation of the fusimotor system is reserved for the control of, or preparation for, movement. In animals, there is now strong evidence that there is usually a tonic component of fusimotor action during rhythmical movements. (ii) During fast, unloaded movements (peak muscle speeds, 0.2 resting lengths/s or more), the firing of both la and II afferents usually increases during lengthening and decreases during shortening. Ib afferents fire during even the most rapid active shortening of their parent muscles, (iii) During powerful shortening contractions performed against significant loads, la firing is often appreciable, suggesting that there is at least some underlying alpha–gamma coactivation. (iv) During fast imposed muscle stretches, la afferents respond with segmented bursts of firing (threshold speed for segmentation, 0.5–1.0 resting length/s). Ib afferents show far less segmentation of discharge under similar circumstances, (v) There are substantial numbers of tendon organ receptors which fire during tasks involving low levels of force.


2007 ◽  
Vol 180 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Leah R. Bent ◽  
P. S. Bolton ◽  
V. G. Macefield
Keyword(s):  

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