Biomaterial Database

Effects of fusimotor stimulation on the response of the secondary ending of the muscle spindle to sinusoidal stretching. 1977

P D Cussons, and M Hulliger, and P B Matthews

1. The responsiveness of the spindle secondary ending to sinusoidal stretching has been studied using the soleus muscle of the anaesthetized cat. The sensitivity (impulses/sec firing per mm stretching) and the phase of the response were determined by computer averaging. The small linear range was studied at frequencies of 0.5-500 Hz, and also the larger non-linear range at 1 Hz.2. In the linear range, stimulation of single fusimotor fibres (which were presumed to be static axons) approximately halved the sensitivity of the ending to low frequency stretching (up to 30 Hz), but did not produce any change in the phase of the response. Thus, from the point of view of motor function, fusimotor activity provides control of gain and a biasing signal, but not control of the relative sensitivity of the secondary ending to length and velocity.3. In contrast, such stimulation slightly increased the responsiveness of the secondary ending to high-frequency stretching (100-500 Hz) and slightly advanced the phase of the response above that of the passive ending.4. The results are discussed in relation to the effect of static fusimotor stimulation on the primary ending, and to findings on secondary endings in the decerebrate cat.

UI	MeSH Term	Description	Entries
D009046	Motor Neurons	Neurons which activate MUSCLE CELLS.	Neurons, Motor,Alpha Motorneurons,Motoneurons,Motor Neurons, Alpha,Neurons, Alpha Motor,Alpha Motor Neuron,Alpha Motor Neurons,Alpha Motorneuron,Motoneuron,Motor Neuron,Motor Neuron, Alpha,Motorneuron, Alpha,Motorneurons, Alpha,Neuron, Alpha Motor,Neuron, Motor
D009047	Motor Neurons, Gamma	Motor neurons which activate the contractile regions of intrafusal SKELETAL MUSCLE FIBERS, thus adjusting the sensitivity of the MUSCLE SPINDLES to stretch. Gamma motor neurons may be "static" or "dynamic" according to which aspect of responsiveness (or which fiber types) they regulate. The alpha and gamma motor neurons are often activated together (alpha gamma coactivation) which allows the spindles to contribute to the control of movement trajectories despite changes in muscle length.	Neurons, Fusimotor,Neurons, Gamma Motor,Gamma Motorneurons,Motor Neurons, Gamma-Efferent,Fusimotor Neuron,Fusimotor Neurons,Gamma Motor Neuron,Gamma Motor Neurons,Gamma Motorneuron,Gamma-Efferent Motor Neuron,Gamma-Efferent Motor Neurons,Motor Neuron, Gamma,Motor Neuron, Gamma-Efferent,Motor Neurons, Gamma Efferent,Motorneuron, Gamma,Motorneurons, Gamma,Neuron, Fusimotor,Neuron, Gamma Motor,Neuron, Gamma-Efferent Motor,Neurons, Gamma-Efferent Motor
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D009431	Neural Conduction	The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus.	Nerve Conduction,Conduction, Nerve,Conduction, Neural,Conductions, Nerve,Conductions, Neural,Nerve Conductions,Neural Conductions
D009470	Muscle Spindles	Skeletal muscle structures that function as the MECHANORECEPTORS responsible for the stretch or myotactic reflex (REFLEX, STRETCH). They are composed of a bundle of encapsulated SKELETAL MUSCLE FIBERS, i.e., the intrafusal fibers (nuclear bag 1 fibers, nuclear bag 2 fibers, and nuclear chain fibers) innervated by SENSORY NEURONS.	Muscle Stretch Receptors,Neuromuscular Spindles,Receptors, Stretch, Muscle,Stretch Receptors, Muscle,Muscle Spindle,Muscle Stretch Receptor,Neuromuscular Spindle,Receptor, Muscle Stretch,Receptors, Muscle Stretch,Spindle, Muscle,Spindle, Neuromuscular,Spindles, Muscle,Spindles, Neuromuscular,Stretch Receptor, Muscle
D009475	Neurons, Afferent	Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.	Afferent Neurons,Afferent Neuron,Neuron, Afferent
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia