[The significance of motor activity in regulating the cholinergic sensitivity of cat muscle spindles].

Following a complete transection of the spinal cord at the Th12-L1, an augmented chemosensitivity of the nuclear bag and nuclear chain fibres was observed. The supersensitivity of the intrafusal fibres to subecholine was higher than to acetylcholine. The supersensitivity of the intrafusal muscle fibres against the background of intact anatomical projections suggests that the motor activity rather than axonal transport plays the leading role in regulation of the cholinergic sensitivity of intrafusal muscle fibres.