[Skeletal muscle motor unit activity in cats during cold tremors].

The electrical activity of single motor units of the cat m. sartorious during the preshivering tone and shivering tremor revealed a steady frequency 5--10/sec. The transition from preshivering tone to shivering tremor involved recruitment of motor units with similar properties: the low--threshold units. The response of motor units to local thermal stimuli applied to vascular thermoreceptors depended on the level of peripheral temperature.