Characteristic curves of the dynamic response of primary muscle spindle endings with and without gamma stimulation
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The characteristic curves of the dynamic response of primary muscle spindle endings (i.e. the dependence of dynamic response on the stretch volocity) have been recorded with and without gamma stimulation in 75 muscle spindles of the cats' M. tibialis anterior. They can be described by a power function DR=a · v r. n
Under dynamic fusimotor stimulation the prefactor ‘a’ increases and the exponent ‘n’ decreases; under static gamma stimulation vice versa.
The characteristic curves with and without gamma stimulations of a single spindle are intersecting, because of the change of the exponent ‘n’.
The dyamic response under dynamic gamma stimulation usually increases, but we observed a decrease, too. Under static gamma stimulation the dynamic response usually decreases.
In the following we looked on the gamma stimulations statistically. We had 47 dynamic gamma stimulations. Here we observed a separation into an upper and a lower group of the characteristic curves, which proved to be statistically significant, according to their effects on the course of the characteristic curves and the velocity sensitivity.
The lower group of the dynamic gamma stimulations and all 24 static gamma stimulations do not differ significantly i) from the group of characteristic curves without gamma stimulation and ii) in the absolute course of the characteristic curves and in the velocity sensitivity under gamma stimulation.
The upper group of dynamic gamma stimulations is the only one to cause significantly strong effects on the course of the characteristic curves and velocity sensitivity.
The upper group of dynamic gamma fibre stimulations extends the measurable velocity range to very small stretch velocities, which otherwise do not cause a measurable dynamic response.
Key wordsGamma stimulation Primary muscle spindle ending Characteristic curves Velocity sensitivity Dynamic response
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- Bessou P, Laporte Y, Pages B (1966) Similitude des effets (statiques ou dynamiques) exercés par des fibres fusimotrices uniques sur les terminaisons primaires de plusieurs fuseaux chez le chat. J Physiol (Paris) 58:31–39Google Scholar
- Brown MC, Crowe A, Matthews PBC (1965) Observations on the fusimotor fibres in the tibialis posterior muscle of the cat. J Physiol (Lond) 177:140–159Google Scholar
- Crowe A, Matthews PBC (1964a) The effects of stimulation of static and dynamic fusimotor fibres on the response to stretching of the primary endings of muscle spindle. J Physiol (Lond) 174:109–131Google Scholar
- Crowe A, Matthews PBC (1964b) Further studies of static and dynamic fusimotor fibres. J Physiol (Lond) 174:132–151Google Scholar
- Emonet-Denand F, Laporte Y, Mathews PBC, Petit J (1977) On the subdivision of static and dynamic fusimotor actions on the primary endings of the cat muscle spindle. J Physiol (Lond) 268:827–861Google Scholar
- Emonet-Denand F, Jami L, Laporte Y, Tankov N (1980) Glycogen depletion of bag1 fibres elicited by stimulation of static y axons in cat peroneus brevis muscle spindles. J Physiol (Lond) 302:311–321Google Scholar
- Goodwin GM, Hulliger M, Matthews PBC (1975) The effects of fusimotor stimulation during small amplitude stretching on the frequency response of primary endings of the mammalian muscle spindle. J Physiol (Lond) 253:175–206Google Scholar
- Hulliger M, Matthews PBC, Noth J (1977) Static and dynamic fusimotor stimulation on the response of Ia fibres to low frequency sinusoidal stretching of widely ranging amplitudes. J Physiol (Lond) 267:811–838Google Scholar
- Hunt CC, Wilkinson RS (1980) An analysis of receptor potential and tension of isolated cat muscle spindles in response to sinusoidal stretch. J Physiol (Lond) 302:241–262Google Scholar
- Matthews PBC (1962) The differentiation of two types of fusimotor fibers by their effects on the dynamic response of muscle spindle primary endings. Quart J Exp Physiol 47:324–333Google Scholar
- Matthews PBC (1972) Mammalian muscle receptors and their central action. E. Arnold Ltd., LondonGoogle Scholar
- Ottoson D, Shepherd GM (1965) Receptor potentials and impulse generation in the isolated spindle during controlled extension. Symp Quant Biol 30:105–114Google Scholar
- Poppele RE (1967) Response of gamma and alpha motor systems to phasic and tonic vestibular inputs. Brain Res 6:535–547Google Scholar
- Rymer WZ, Houk JC, Crago PE (1977) The relation between dynamic response and velocity sensitivity for muscle spindle receptors. Proceedings of the international union of physiological sciences XIII:647 (Paris)Google Scholar
- Schäfer SS, Schäfer S (1969) Die Eigenschaften einer primären Muskelspindel-Afferenz bei rampenförmiger Dehnung und ihre mathematische Beschreibung. Pflügers Arch 310:206–228Google Scholar
- Schäfer SS (1973) The characteristic curves of the dynamic response of primary muscle spindle endings in the absence and presence of stimulation of fusimotor fibers. Brain Res 59:395–399Google Scholar
- Stevens SS (1971) Sensory power functions and neural events. In: Loewenstein WR (ed) Principles of receptor physiology: Handbook of sensory physiology, vol 1, Springer, Berlin Heidelberg New York, pp 226–242Google Scholar
- Sugi H (1972) Tension changes during and after stretch in frog muscle fibres. J Physiol (Lond) 225:237–253Google Scholar
- Takano K, Henatsch HD (1964) Direkte Aufnahme von Längen-Reflexpannungs-Diagrammen einzelner Muskeln in situ. Pflügers Arch Ges Physiol 281:105Google Scholar