Biomaterial Database

On the specificity of sensory reinnervation of cat skeletal muscle. 1986

W F Collins, and L M Mendell, and J B Munson

Experiments were addressed to the following questions: when a muscle nerve is sectioned and regenerates to what extent are muscle receptors (spindles and tendon organs) reinnervated? is the reinnervation specific? that is, do group Ia and spindle group II fibres preferentially reinnervate spindles and do group Ib fibres preferentially reinnervate tendon organs? what are the consequences to the afferent of failure to re-establish appropriate receptor innervation? In normal cats, and in cats 3, 6 or 9 months after section and resuture of the medial gastrocnemius muscle nerve, medial gastrocnemius afferent fibres in continuity were impaled in dorsal rootlets for recording and stimulation. Receptor innervation was determined electrophysiologically by manipulation of the medial gastrocnemius muscle. Afferent fibre type was determined by the presence (group Ia or spindle group II) or absence (group Ib) of field potentials in the homonymous motoneurone pool in response to activation of the afferent fibre. In normal cats, two-thirds of recorded afferents innervated spindles; 89% of these generated field potentials detected in the motoneurone pool. One-third of recorded afferents innervated tendon organs; none of these generated such field potentials. In operated cats, about half of the recorded afferents innervated spindles, about one-third responded abnormally or not at all to muscle manipulation, and fewer than one-tenth innervated tendon organs. Numbers of afferents which innervated spindles increased with time. The proportion of afferents generating field potentials was smaller in operated than in normal animals (40% vs. 60%) and declined progressively with time. Field potentials were generated by fibres in all categories of receptor reinnervation. This ability was lost at long post-operative intervals by fibres failing to reach the muscle. Conduction velocity of fibres fell in operated animals. Fibres reinnervating their original type of receptor (e.g. group Ia fibre----spindle) exhibited greater conduction velocity than fibres innervating an inappropriate receptor or no receptor. From these findings and other considerations (see Discussion) we conclude that following section and resuture of the medial gastrocnemius muscle nerve: about 75% of afferents regenerate into the medial gastrocnemius muscle, many more spindles than tendon organs become reinnervated, random populations of groups Ia and Ib (and probably spindle group II) fibres reinnervate spindles, fibres which fail to re-establish appropriate receptor innervation also fail to recover normal conduction velocity.(ABSTRACT TRUNCATED AT 400 WORDS)

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008465	Mechanoreceptors	Cells specialized to transduce mechanical stimuli and relay that information centrally in the nervous system. Mechanoreceptor cells include the INNER EAR hair cells, which mediate hearing and balance, and the various somatosensory receptors, often with non-neural accessory structures.	Golgi Tendon Organ,Golgi Tendon Organs,Krause's End Bulb,Krause's End Bulbs,Mechanoreceptor,Mechanoreceptor Cell,Meissner's Corpuscle,Neurotendinous Spindle,Neurotendinous Spindles,Receptors, Stretch,Ruffini's Corpuscle,Ruffini's Corpuscles,Stretch Receptor,Stretch Receptors,Mechanoreceptor Cells,Bulb, Krause's End,Bulbs, Krause's End,Cell, Mechanoreceptor,Cells, Mechanoreceptor,Corpuscle, Meissner's,Corpuscle, Ruffini's,Corpuscles, Ruffini's,End Bulb, Krause's,End Bulbs, Krause's,Krause End Bulb,Krause End Bulbs,Krauses End Bulb,Krauses End Bulbs,Meissner Corpuscle,Meissners Corpuscle,Organ, Golgi Tendon,Organs, Golgi Tendon,Receptor, Stretch,Ruffini Corpuscle,Ruffini Corpuscles,Ruffinis Corpuscle,Ruffinis Corpuscles,Spindle, Neurotendinous,Spindles, Neurotendinous,Tendon Organ, Golgi,Tendon Organs, Golgi
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
D009121	Muscle Denervation	The resection or removal of the innervation of a muscle or muscle tissue.	Denervation, Muscle,Denervations, Muscle,Muscle Denervations
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D009416	Nerve Regeneration	Renewal or physiological repair of damaged nerve tissue.	Nerve Tissue Regeneration,Nervous Tissue Regeneration,Neural Tissue Regeneration,Nerve Tissue Regenerations,Nervous Tissue Regenerations,Neural Tissue Regenerations,Regeneration, Nerve,Regeneration, Nerve Tissue,Regeneration, Nervous Tissue,Regeneration, Neural Tissue,Tissue Regeneration, Nerve,Tissue Regeneration, Nervous,Tissue Regeneration, Neural
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