Time coupling of skeletomotor discharges in response to pseudo-random transsynaptic and transmembrane stimulation.

Firing pattern of skeletomotor neurones innervating triceps surae muscles in response to pseudo-random muscle stretching and white noise modulated transmembrane current stimulation was investigated in decerebrate cats. Pseudo-random muscle stretching (upper cut-off frequency 60 Hz, amplitude sigma (standard deviation) ranging from 18.5 microns to 40 microns) was applied to triceps surae muscles.

Reflex effects on gamma fusimotor neurones of chemically induced discharges in small-diameter muscle afferents in decerebrate cats.

The effects on fusimotor discharge rate of algesic agents (bradykinin, potassium chloride, histamine, 5-hydroxytryptamine) and lactic acid, applied by close arterial injection into triceps surae muscles, were investigated in decerebrate cats. Fusimotor discharge was recorded from filaments dissected free from otherwise intact nerves to the triceps muscles. The substances applied induced an increase in discharge rate of spontaneously active gamma fusimotor neurones as well as a recruitment of previously silent ones.

[Proprioceptive reflexes and the regulation of movement].

Apart from the direct influences of muscle spindle sensory endings on skeletomotor neurones a great deal of their reflex drive is provided indirectly via the gamma-loop. Fusimotor neurones modulate their discharge rate in parallel with that of the skeletomotor neurones during the rising phase, as well as during the maintained reflex tension in m.triceps surae of decerebrated cat, when small tension oscillations are present in the muscle.

Reflex responses of fusimotoneurons to sinusoidal muscle stretching.

Reflex response of fusimotoneurons to sinusoidal muscle stretching were investigated in decerebrated cats. Nerve impulses of single fusimotoneurons were recorded from thin filaments dissected from otherwise intact nerves to triceps surae muscles. Amplitude of the sinusoidal stretching of these muscles was 3 mm peak-to-peak and the frequencies 0.

The study of locomotion by finite state models.

A methodology to derive finite state models of legged locomotion is outlined. Background data for model derivation are joint angle functions and gait diagrams. The method is used to describe the walking of the cat in terms of an abstract automaton.