Modulations of fusimotor discharge induced by tension changes during reflex muscle contraction

Abstract

An increase followed by a transient decrease in the spike occurrence of fusimotor neurones, with a destination in triceps surae muscles, has been found at the rising phase of reflex muscle contraction induced by vibration (Anastasijević and Vučo, 1982, 1984). The initial transient response of fusimotor neurones, in a way similar to the silencing of the skeletomotor output, indicates an alpha-gamma coactivity at that instant of reflex muscle contraction. In view of these findings it seemed to us valuable to explore the spike occurrence of fusimotor neurones during the subsequent tension irregularities of isometric reflex contraction induced by triceps surae muscles vibration.