Phase-frequency characteristics of afferent activity and depolarization of primary afferents during passive displacement of the hindlimb of the cat

Frequency response characteristics of afferent activity and primary afferent depolarization (PAD) evoked by this activity were investigated in decerebrated cats during passive movement of hindlimb in ankle joint. At the frequencies of 0.2-1.7 Hz the lead of the level of depolarization was determined by the value of phase changes of afferent activity. Above 1.7 Hz a phase lag of the level of depolarization was observed. This lag was caused by the dynamic properties of PAD generation system.