The distribution of static gamma-axons in the tenuissimus muscle of the cat.

AUTOR(ES)

Banks, R W

RESUMO

1. The distribution of static gamma-axons within and among muscle spindles of the tenuissimus muscle has been studied in the anaesthetized cat, on the basis of the effects on the responses of primary endings when bag2 or chain fibres or both are activated by static gamma-stimulation. 2. Locations of spindles were marked for subsequent histological analysis using teased, silver-impregnated preparations. 3. Static effects were classified into: (i) biassing; (ii) driving; or (iii) indeterminate categories. 4. Critical correlations established that the biassing type was produced by bag2 activity, either alone or in combination with chain fibres, whereas the driving type was produced by chain fibres active alone. Indirect evidence suggested that indeterminate effects were produced by bag2 and chain fibres active together. 5. The static gamma-axons showed some differential distribution according to their conduction velocities: faster-conducting axons were likely to be more widely distributed among spindles but less likely to innervate chain fibres alone than were more slowly conducting axons. 6. The results are discussed in terms of their possible functional and developmental significance.

Documentos Relacionados

• Glycogen depletion elicited in tenuissimus intrafusal muscle fibres by stimulation of static gamma-axons in the cat.
• Incidence of non-driving excitation of Ia afferents during ramp frequency stimulation of static gamma-axons in cat hindlimbs.
• Intrafusal motor innervation: a quantitative histological analysis of tenuissimus muscle spindles in the cat.
• Activation of cat muscle spindles by static skeletofusimotor axons.
• Free nerve endings in skeletal muscle of the cat.