Journal ArticleDOI
An evaluation of length and force feedback to soleus muscles of decerebrate cats.
J C Houk,J J Singer,M R Goldman +2 more
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This work has attempted to determine whether or not this regulation of force by signals from tendon organs is significant in decerebrate cats.Abstract:
IT IS NOW WELL KNOWN that contraction of a muscle is reflexly excited by responses of its spindle receptors to stretch (32, 34) and is reflexly inhibited by responses of its Golgi tendon organs to contraction (10, 31). Many experimental techniques have been used to confirm these observations (7, 12, 23). Nevertheless, the actual importance of each of these reflexes in the gradation of contraction remains obscure because of the lack of an experimental approach which is capable of estimating quantitatively their respective influences (39). Formerly it was believed by many that tendon organs responded and inhibited contraction on1 .y when muscular forces became excessive. Recent studies (19, 26) have cast doubt on this hypothesis by demonstrating for these receptors a much lower threshold to must ular contract ion than was previ not ouslv t .h assure ought. This find .ing alone does a con tinuo us regulation of muscular force by signals from tendon organs since impulses must be transmitted through one or two interneurons before they may inhibit homonymous motoneurons (7, 31). Studies have shown that these Ib pathways transmit impulses more effectively in spinal than in decerebrate cats (8). It is therefore likely that the gain of this reflex pathway is not constant but, rather, is subject to control by signals from various regions of the nervous system. For example, Ib pathways are facilitated by signals transmitted from the red nucleus (IS). As a result, the relative importance of tendon organs in the regulation of contraction would depend on the particular state of the experimental animal. We have attempted to determine whether or not this regulation of force is significant in decerebrate cats.read more
Citations
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Anthropomorphic robotics
TL;DR: In this paper, a working computational model is proposed that organizes the massive computational load into a structure which is composed of a small number of computational units and lends itself to parallel computation.
Journal ArticleDOI
Resetting of resultant stiffness in ankle flexor and extensor muscles in the decerebrate cat.
TL;DR: The results show that reflex gain is not determined solely by the level of motoneuronal excitability but also by a descending control from the brainstem, and that the lower resultant stiffness in flexors compared to extensors in the decerebrate cat is set by this control system and not by inherent differences in the strength of autogenetic reflex pathways for the two muscles.
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Nonlinear joint angle control for artificially stimulated muscle
TL;DR: Designs of both open- and closed-loop controllers of electrically stimulated muscle that explicitly depend on a nonlinear mathematical model of muscle input-output properties are presented and evaluated and an open-loop nonlinear compensator was tested in an animal model.
Journal ArticleDOI
The influence of extrafusal muscle activity on discharge patterns of primary muscle spindle endings.
Uwe Windhorst,J. Meyer-Lohmann +1 more
TL;DR: It is concluded that primary endings react very sensitively to local extrafusal events and the CNS receives much more accurate information about these events in the correlation of several Ia afferents than in the discharge of a single fibre.
Book ChapterDOI
Limitations in the servo-regulation of soleus muscle stiffness in premammillary cats
TL;DR: The data suggest that in the premammillary decerebrate the gain of Golgi tendon organ feedback is negligibly low; the observed reflex effects are attributed to spindle group Ia and II feedback.
References
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Journal ArticleDOI
Functional significance of cell size in spinal motoneurons
TL;DR: The present paper is concerned with the central part of the motoneuron and the significance of its size in synaptic transmission and asks whether the cell bodies (and dendrites) connected with large and small motor fibers have different functional properties which can be recognized by their discharge characteristics.
Journal ArticleDOI
Excitability and inhibitibility of motoneurons of different sizes
TL;DR: It was concluded tentatively that the size or surface area of a motoneuron determines its excitability and hence its responsiveness to stretch-evoked impulses and if this conclusion is correct, it may infer that size is a prime determinant of excitability throughout the nervous system.
Journal ArticleDOI
Responses of Golgi tendon organs to active contractions of the soleus muscle of the cat.
J Houk,E Henneman +1 more
Journal ArticleDOI
The mechanical properties of cat soleus muscle during controlled lengthening and shortening movements
TL;DR: By supplying pulses to different subdivisions of the ventral nerve roots in rotation, it was possible to obtain smooth contractions of cat soleus with low rates of stimulation.
Journal ArticleDOI
An analysis of the mechanical components in frog's striated muscle.
B. R. Jewell,D. R. Wilkie +1 more
TL;DR: J. R. Wilkie striated muscle An analysis of the mechanical components in frog's This information is current as of March 19, 2008 and has been published is the official journal of The Journal of Physiology Online.
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