Recordings from a semitendinousus motoneurone. A and B, repetitive firing elicited by a rectangular current pulse alone (A) and together with recurrent inhibition (B). C and D, repetitive firing evoked by a train of impulses to the CST alone (C) and together with recurrent inhibition (D). Each alternative was repeated 20 times and the means and s.d. are shown as a bar graph in F. E, the recurrent inhibition (90 stimuli at 100 Hz, 5 ×T) and the EPSP evoked by the CST stimulation (14 stimuli at 200 Hz) used in B–D, but here recorded at a membrane potential close to firing threshold. The records were low frequency (1 Hz) filtered.