Activity of a pyramidal tract projecting neuron (PTN) of the motor cortex during walking on the flat surface and horizontal ladders with crosspieces 18, 12 and 5 cm wide. In all ladders the crosspieces had flat tops and were positioned 25 cm apart. Cell was recorded in track 22 of cat 7. Latent period of cells’ response to electrical stimulation of the pyramidal tract was 0.9 ms; collision test was satisfied. The cell was activated by flexion of the contralateral shoulder, that is, the shoulder forward movement.